chromosome

A chromosome is a single large macromolecule of DNA, and constitutes a physically organized form of DNA in a cell. It is a very long, continuous piece of DNA (a single DNA molecule), which contains many genes, regulatory elements and other intervening nucleotide sequences. A broader definition of "chromosome" also includes the DNA-bound proteins which serve to package and manage the DNA. The word chromosome comes from the Greek χρῶμα (chroma, color) and σῶμα (soma, body) due to its capacity to be stained very strongly with vital and supravital dyes.

Chromosomes vary extensively between different organisms. The DNA molecule may be circular or linear, and can contain anything from tens of kilobase pairs to hundreds of megabase pairs. Typically eukaryotic cells have large linear chromosomes and prokaryotic cells smaller circular chromosomes, although there are many exceptions to this rule. Furthermore, cells may contain more than one type of chromosome; for example mitochondria in most eukaryotes and chloroplasts in plants have their own small chromosome in addition to the nuclear chromosomes.

In eukaryotes nuclear chromosomes are packaged by proteins (particularly histones) into chromatin to fit the massive molecules into the nucleus. The structure of chromatin varies through the cell cycle, and is responsible for the compaction of DNA into the classic four-arm structure during mitosis and meiosis. Prokaryotes do not form chromatin, the cells lack proteins required and the circular configuration of the molecule prevents this.

"Chromosome" is a rather loosely defined term. In prokaryotes, a small circular DNA molecule may be called either a plasmid or a small chromosome. In viruses, mitochondria, and chloroplasts their DNA molecules are commonly referred to as chromosomes, despite being naked molecules, as they constitute the complete genome of the organism or organelle.

Chromosomes in eukaryotes
Eukaryotes (cells with nuclei such as plants, yeast, and animals) possess multiple large linear chromosomes contained in the cell's nucleus. Each chromosome has one centromere, with one or two arms projecting from the centromere, although under most circumstances these arms are not visible as such. In addition most eukaryotes have a small circular mitochondrial genome, and some eukaryotes may have additional small circular or linear cytoplasmic chromosomes.

In the nuclear chromosomes of eukaryotes, the uncondensed DNA exists in a semi-ordered structure, where it is wrapped around histones (structural proteins), forming a composite material called chromatin.


Chromatin
Main article: Chromatin

Fig. 2: The major structures in DNA compaction; DNA, the nucleosome, the 10nm "beads-on-a-string" fibre, the 30nm fibre and the metaphase chromosome.Chromatin is the complex of DNA and protein found in the eukaryotic nucleus which packages chromosomes. The structure of chromatin varies significantly between different stages of the cell cycle, according to the requirements of the DNA.


Interphase chromatin
During interphase (the period of the cell cycle where the cell is not dividing) two types of chromatin can be distinguished:

Euchromatin, which consists of DNA that is active, e.g., expressed as protein.
Heterochromatin, which consists of mostly inactive DNA. It seems to serve structural purposes during the chromosomal stages. Heterochromatin can be further distinguished into two types:
Constitutive heterochromatin, which is never expressed. It is located around the centromere and usually contains repetitive sequences.
Facultative heterochromatin, which is sometimes expressed.
Individual chromosomes cannot be distinguished at this stage - they appear in the nucleus as a homogeneous tangled mix of DNA and protein.


Metaphase chromatin and division
See also: mitosis and meiosis

Human chromosomes during metaphase.In the early stages of mitosis or meiosis (cell division), the chromatin strands become more and more condensed. They cease to function as accessible genetic material (transcription stops) and become a compact transportable form. This compact form makes the individual chromosomes visible, and they form the classic four arm structure, a pair of sister chromatids attach to each other at the centromere. The shorter arms are called p arms (from the French petit, small) and the longer arms are called q arms (q follows p in the Latin alphabet). This is the only natural context in which individual chromosomes are visible with an optical microscope.

During divisions long microtubules attach to the centromere and the two opposite ends of the cell. The microtubules then pull the chromatids apart, so that each daughter cell inherits one set of chromatids. Once the cells have divided, the chromatids are uncoiled and can function again as chromatin. In spite of their appearance, chromosomes are structurally highly condensed which enables these giant DNA structures to be contained within a cell nucleus (Fig. 2).

The self assembled microtubules form the spindle, which attaches to chromosomes at specialized structures called kinetochores, one of which is present on each sister chromatid. A special DNA base sequence in the region of the kinetochores provides, along with special proteins, longer-lasting attachment in this region.


Chromosomes in prokaryotes
Prokaryotes (eg. Bacteria) typically have a single circular chromosome, but many variations do exist. Bacterial DNA also exists as plasmids, essentially miniature chromosomes, which are small circular pieces of DNA that are readily transmitted between bacteria. The distinction between plasmids and chromosomes is poorly defined, though size and necessity are generally taken into account.


[edit] Structure in sequences
Prokaryotes chromosomes have less sequence based structure than eukaryotes. They do, however, typically have a single point, the origin of replication, from which replication starts.

The genes in prokaryotes are often organised in operons, and do not contain introns, unlike eukaryotes.


Location in the cell
Bacterial chromosomes tend to be tethered to the plasma membrane of the bacteria. In molecular biology application, this allows for its isolation from plasmid DNA by centrifugation of lysed bacteria and pelleting of the membranes (and the attached DNA).


DNA packaging
Prokaryotes do not possess histones or nuclei, and so do not possess chromatin like eukaryotes. There is, however, thought to be some structural organisation to help condense the large molecule into the small prokaryotic cell.

Prokaryotic chromosomes and plasmids are, like eukaryotic DNA, generally supercoiled. The DNA must first be released into its relaxed state for access for transcription, regulation, and replication.

Chromosomes in prokaryotes
Prokaryotes (eg. Bacteria) typically have a single circular chromosome, but many variations do exist. Bacterial DNA also exists as plasmids, essentially miniature chromosomes, which are small circular pieces of DNA that are readily transmitted between bacteria. The distinction between plasmids and chromosomes is poorly defined, though size and necessity are generally taken into account.


Structure in sequences
Prokaryotes chromosomes have less sequence based structure than eukaryotes. They do, however, typically have a single point, the origin of replication, from which replication starts.

The genes in prokaryotes are often organised in operons, and do not contain introns, unlike eukaryotes.


Location in the cell
Bacterial chromosomes tend to be tethered to the plasma membrane of the bacteria. In molecular biology application, this allows for its isolation from plasmid DNA by centrifugation of lysed bacteria and pelleting of the membranes (and the attached DNA).


DNA packaging
Prokaryotes do not possess histones or nuclei, and so do not possess chromatin like eukaryotes. There is, however, thought to be some structural organisation to help condense the large molecule into the small prokaryotic cell.

Prokaryotic chromosomes and plasmids are, like eukaryotic DNA, generally supercoiled. The DNA must first be released into its relaxed state for access for transcription, regulation, and replication.


Normal members of a particular eukaryotic species all have the same number of nuclear chromosomes (see the table). Other eukaryotic chromosomes, i.e. mitochondrial and plasmid-like small chromosomes, are much more variable in number, and there may be thousands of copies per cell.

Asexually reproducing species have one set of chromosomes, which is the same in all body cells.

Sexually reproducing species have somatic cells (body cells), which are diploid [2n] having two sets of chromosomes, one from the mother and one from the father. Gametes, reproductive cells, are haploid [n]: they have one set of chromosomes. Gametes are produced by meiosis of a diploid germ line cell. During meiosis, the matching chromosomes of father and mother can exchange small parts of themselves (crossover), and thus create new chromosomes that are not inherited solely from either parent. When a male and a female gamete merge (fertilization), a new diploid organism is formed.

Some animal and plant species are polyploid [Xn]: they have more than two sets of homologous chromosomes. Agriculturally important plants such as tobacco or wheat are often polyploid compared to their ancestral species. Wheat has a haploid number of seven chromosomes, still seen in some cultivars as well as the wild progenitors. The more common pasta and bread wheats are polyploid having 28 (tetraploid) and 42 (hexaploid) chromosomes compared to the 14 (diploid) chromosomes in the wild wheat.[4]

Historical note: In 1921, Theophilus Painter claimed, based on his observations, that human sex cells had 24 chromosomes each, giving humans 48 chromosomes total. It wasn't until 1955 that the number of chromosomes was clearly shown to be 23.

Prokaryotes
Prokaryote species generally have one copy of each major chromosome, but most cells can easily survive with multiple copies. Plasmids and plasmid-like small chromosomes are, like in eukaryotes, very variable in copy number. The number of plasmids in the cell is almost entirely determined by the rate of division of the plasmid - fast division causes high copy number, and vice versa.


Chromosomal aberrations
Main articles: Chromosome abnormalities and aneuploidy

The three major single chromosome mutations; deletion (1), duplication (2) and inversion (3).
The two major two-chromosome mutations; insertion (1) and translocation (2).
In Down syndrome, chromosome 21 is affectedChromosomal aberrations are disruptions in the normal chromosomal content of a cell, and are a major cause of genetic disease in humans, such as Down syndrome. Some chromosome abnormalities do not cause disease in carriers, such as translocations, or chromosomal inversions, although they may lead to a higher chance of having a child with a chromosome disorder. Abnormal numbers of chromosomes or chromosome sets, aneuploidy, may be lethal or give rise to genetic disorders. Genetic counseling is offered for families that may carry a chromosome rearrangement.

The gain or loss of chromosome material can lead to a variety of genetic disorders. Human examples include:

Cri du chat, which is caused by the deletion of part of the short arm of chromosome 5. "Cri du chat" means "cry of the cat" in French, and the condition was so-named because affected babies make high-pitched cries that sound like a cat. Affected individuals have wide-set eyes, a small head and jaw and are moderately to severely mentally retarded and very short.
Wolf-Hirschhorn syndrome, which is caused by partial deletion of the short arm of chromosome 4. It is characterized by severe growth retardation and severe to profound mental retardation.
Down's syndrome, usually is caused by an extra copy of chromosome 21 (trisomy 21). Characteristics include decreased muscle tone, asymmetrical skull, slanting eyes and mild to moderate mental retardation.
Edward's syndrome, which is the second most common trisomy after Down syndrome. It is a trisomy of chromosome 18. Symptoms include mental and motor retardation and numerous congenital anomalies causing serious health problems. Ninety percent die in infancy; however, those who live past their first birthday usually are quite healthy thereafter. They have a characteristic hand appearance with clenched hands and overlapping fingers.
Patau Syndrome, also called D-Syndrome or trisomy-13. Symptoms are somewhat similar to those of trisomy-18, but they do not have the characteristic hand shape.
Idic15, abbreviation for Isodicentric 15 on chromosome 15; also called the following names due to various researches, but they all mean the same; IDIC(15), Inverted dupliction 15, extra Marker, Inv dup 15, partial tetrasomy 15
Jacobsen syndrome, also called the terminal 11q deletion disorder.[1] This is a very rare disorder. Those affected have normal intelligence or mild mental retardation, with poor expressive language skills. Most have a bleeding disorder called Paris-Trousseau syndrome.
Klinefelter's syndrome (XXY). Men with Klinefelter syndrome are usually sterile, and tend to have longer arms and legs and to be taller than their peers. Boys with the syndrome are often shy and quiet, and have a higher incidence of speech delay and dyslexia. During puberty, without testosterone treatment, some of them may develop gynecomastia.
Turner syndrome (X instead of XX or XY). In Turner syndrome, female sexual characteristics are present but underdeveloped. People with Turner syndrome often have a short stature, low hairline, abnormal eye features and bone development and a "caved-in" appearance to the chest.
XYY syndrome. XYY boys are usually taller than their siblings. Like XXY boys and XXX girls, they are somewhat more likely to have learning difficulties.
Triple-X syndrome (XXX). XXX girls tend to be tall and thin and are often shy. They have a higher incidence of dyslexia.
Small supernumerary marker chromosome. This means there is an extra, abnormal chromosome. Features depend on the origin of the extra genetic material. Cat-eye syndrome and isodicentric chromosome 15 syndrome (or Idic15) are both caused by a supernumerary marker chromosome, as is Pallister-Killian syndrome.
Chromosomal mutations produce changes in whole chromosomes (more than one gene) or in the number of chromosomes present.

Deletion- loss of part of a chromosome
Duplication- extra copies of a part of a chromosome
Inversion- reverse the direction of a part of a chromosome
Translocation- part of a chromosome breaks off and attaches to another chromosome
Most mutations are neutral- have little or no effect

A detailed graphical display of all human chromosomes and the diseases annotated at the correct spot may be found at [2].

The human chromosomes
Human cells have 23 pairs of large linear nuclear chromosomes, giving a total of 46 per cell. In addition to these, human cells have many hundreds of copies of the mitochondrial genome. All of the human chromosomes have been sequenced and a great deal is known about each of them.

math see you are a genuis or not in math

1) The diagram shows a glass cone with a cylindrical hole in the middle. The radius of the hole is 1/5 the radius of the cone. How much glass was used to make the cone, with a hole in the middle, as shown in the diagram?















2) Find y


2 B -2
A -1 C
0 1 -4

3) on the diagram above find A,B, and C

17 X 7
12 22 Z
W Y 27

4) on the diagram above find W,X,Y,Z












5) find h















6) find D









7) The South America Amazon River is about 4000mi. How many feet is the Amazon River?

8)write as a power of 10.
A nanosecond is 0.000000001 of a second

9) When a cricket chirps n times per minute, you can find the temperature F in F= n/4 + 37. Write down a formula to find the number of times a cricket chirps per minute when you know the temperature.

10) A ball is dropped from a height of 64 ft. Each bounce the ball reaches a height that is half the height of the previous bounce. After which bounce will the ball rebound to a maximum height of 6 in ?

11) Elizabeth visits her friend Andrew and then returns home by the same route. She always walks 2km/h when going uphill, 6km/h when going downhill and 3km/h when on level ground. If her total walking time is 6 hours, then what is the total distance she walks in km?

12) Flora had an average of 56% on her first 7 exams. What would she have to make on her eighth exam to obtain an average of 60% on 8 exams?

13) Ian was entering a Math contest for Grade 9. He was working on this particular problem. He was having difficulty with the answer. This was the problem: The integers greater than 1 are arranged, four in each row, in 5 columns, as follows:

a b c d e

2 3 4 5

9 8 7 6

10 11 12 13

17 16 15 14


If he followed the pattern what column would the number 1002 fall in?

14)Stephanie wasn't very keen on Algebra. Her teacher gave her an Algebra problem and told Stephanie to solve it. She was having problems, can you help her?

3x + 7 = x2 + k = 7x + 15
What is the value of k?


15)Why 1 + 1 = 2?

Battojutsu

Battōjutsu (抜刀術, Battōjutsu?) is a Japanese term meaning techniques for drawing a sword. It is often used interchangeably with the terms iaijutsu, battōdō, or iaidō, although each term does have nuances in the Japanese language and different schools of Japanese martial arts may use them to differentiate between techniques (e.g. standing or sitting techniques). The emphasis of training in battōjutsu is on quickly and correctly drawing the sword, striking, and returning the sword to its saya (scabbard/sheath). All terms are somewhat more specific than kenjutsu which more broadly means simply sword techniques, and is often used to refer to techniques where the sword is already out of the saya. Often the emphasis in any form of 'battōjutsu' is on cutting with the draw (i.e. cutting from the saya, rather than first drawing the sword and then engaging an enemy as a separate action).

Comparison with Iaidō, Iaijutsu, etc.
Karl Friday in his book, [[Legacies of the Sword]] discusses the historical usage of various terms in Japanese to describe sword arts. Suffice it to say, that while in English many people may dispute the use of -dō or -jutsu or else ascribe specific differences to the terms battō or iai, these differences are not nearly as clear in the original language and the words are often used interchangably.


History
The origins of drawing the sword from the sheath and cutting on the draw are murky. Although various martial traditions in Japan have legendary founders going back many years, much credit is given to Hayashizaki Jinsuke. He is now enshrined at the Hayashizaki Jinja, a shrine in the Tōhoku region of Japan seen by many modern practitioners as the chief shrine for iai. The concept of battōjutsu may have existed before this time, but it is unclear who was the first person to actually use the term.


Fictional occurrences
In the popular animé and manga series Rurouni Kenshin, the principal hero uses a fictional style of battōjutsu known as Hiten Mitsurugi-Ryū that focuses on the use of "god-like" speed and complex aerial maneuvers.


Outside of Japan
Ryūha, or Japanese martial traditions, which teach battōjutsu are relatively uncommon in Japan, and less common in America and other coutries. This is in contrast to the relatively high degree of availability of open hand training, such as karate and aikidō. Here is a partial list of some of the ryūha taught outside of Japan which include what could be called battōjutsu in the broad sense of drawing and cutting from the saya, although some of them more often use the terms iaidō, iaijutsu, or battōdō.

Listed in the Bugei Ryūha Daijiten (武芸流派大辞典, the Encyclopedia of Martial Arts Traditions) as koryū, or arts developed before the Meiji era.

Musō Jikiden Eishin Ryū -- Traces back to Hasekawa Eishin Ryū, which traces back to the Hayashizaki Ryū Iai of Hayashizaki Junsuke Shigenobu (Late 15th century)
Musō Shinden Ryū -- Traces back to Hasekawa Eishin Ryū, which traces back to the Hayashizaki Ryū Iai of Hayashizaki Junsuke Shigenobu (Late 15th century)
Suio Ryū Iai Kenpō -- Founded around 1600 CE by Mima Yoichizaemon Kagenobu
Shin Shin Sekiguchi Ryū -- Sekiguchi Ryū was founded by Sekiguchi Yorokuuemon Ujimune. Ujimune may have received iai training from Hayashizaki Jinsuke, per the article in Bugei Ryūha Daijiten.
Mugai Ryū -- Founded in 1693 by Tsuji Gettan Sukemochi, who had previously learned Yamaguchi Ryū kenjutsu.
Jigen Ryū -- Founded by Tōgō Hizen-no-kami Shigetada, its lineage traces back through Tenshinshō Jigen Ryū to the Shintō Ryū of Iizasa Chōisai Ienao.
Tenshin Shōden Katori Shintō Ryū -- Founded in the 15th Century by Iizasa Chōisai Ienao.
Yagyū Shinkage Ryū -- From the Shinkage Ryū of Yagyū Muneyoshi, who studied under Kamiizumi Nobutsuna in the 16th Century.
Listed in the Bugei Ryūha Daijiten as arts developed after the beginning of the Meiji era.

Toyama Ryū -- Founded in the late 19th, early 20th century to instruct officers at the Toyama Military Academy.
Nakamura Ryu -- Founded by Nakamura Taizaburō in the mid-20th century, who had learned Toyama Ryū at the Toyama Military Academy.
Not listed in the Bugei Ryūha Daijiten:

Enshin Itto Ryu
Fudo Ikken Ryu

Kenjutsu

Kenjutsu (剣術 : けんじゅつ, Kenjutsu?), meaning the craft, art, or science of the sword, is a Japanese martial art that uses a specific methodology to teach the use of the katana (Japanese sword). Generally, kenjutsu takes the form of partnered practice exercised through kata (pre-arranged forms, as opposed to competition, solo, or freestyle practice).

Kenjutsu in conjunction with kata is the core means by which koryū, which are "old" or "traditional" schools of martial arts, train their students to employ the Japanese swords against a variety of classical weapons, while indoctrinating the student in the combative mindset of the school. Therefore, kenjutsu can be seen as an integral aspect of all classical Japanese sword school curricula.

Today most koryū schools continue to employ kenjutsu as part of their curriculum. Some are even thriving on a relatively small scale. Schools (or ryū) such as Yagyū Shinkage-ryū, Kashima Shinto-ryū, Kashima Shin-ryū, Kashima Shinden Jikishinkage-ryū, Hyoho Niten Ichi-ryū are some of the more famous still existing. Some of these schools trace their lineage to the early years of the Tokugawa shogunate. Many other schools can legitimately trace their history from the founder dating back to the 14th century, such as Maniwa Nen-ryū (founded: 1368) or Tatsumi-ryū (founded: Eisho period 1504-1520) or Kashima Shin-ryū (founded: ca. 1450).

Confusion with other practices
Kenjutsu should not be confused with iaidō or iaijutsu, where the former being a modern development with both sporting, artistic, and meditative features. The role of iaijutsu is as a practice performed against an opponent who is visualized most often to be armed with a sword. There is often strong biomechanical symbiosis between the iaijutsu and kenjutsu of most schools. Iaijutsu allows the practitioner to perfect the execution of techniques, body position and displacement which he/she will later employ in his/her kenjutsu without the stresses of a partnered kata. Iaijutsu therefore remains a distinct and yet a complementary practice to kenjutsu in most schools.

Another general distinction between iaijutsu and kenjutsu is the condition of the sword at the start of the kata. In iaijutsu, the sword starts in the sheathed position with the emphasis on the draw as well as the few initial cuts. Traditionally, koryū focus on shifting smoothly in the pace of execution within the iaijutsu kata with little focus is given to the speed of draw. This is contrasted with kenjutsu, were the sword begins unsheathed, and the emphasis is on both attack and defense. This distinction is however not consistent as some kenjutsu kata start with the sword sheathed.


Equipment
The equipment employed in kenjutsu has changed little in almost five hundred years, with most schools employing a ryū-specific bokken (wooden katana). The style of the bokken is often defined by tradition with the design, weight and feeling of the bokken being specifically chosen so as to allow the techniques of the ryū to be effectively executed. Contrast, for example, the very thin and fast Yagyū bokken which suits the quick and light sword work of Yagyū Shinkage-ryū with the relatively heavy and straight Kashima Shin-ryū bokken which has little taper and which lends itself well to the heavy contact inertial style of the Kashima Shin-ryū.

Some schools employ a fukuro shinai (a bamboo sword covered with leather or cloth) under circumstances where the junior student lacks the ability to safely control a bokken at full speed or as a general safety precaution. The practice of using a fukuro shinai was however not adopted from kendo as the invention of the fukuro shinai dates back to the 15th century. Many schools also practice kenjutsu at advanced levels with unsharpened steel or alloy artificial swords, called iaitō.


Nitōjutsu
A distinguishing feature of many kenjutsu syllabus is the use of a paired ōdachi and kodachi/shotō commonly refereed to nitōjutsu or two sword methods. The most famous exponent of [[nitōjutsu was Musashi Miyamoto, (1584 – 1645) the founder of Hyoho Niten Ichi-ryū. Nitōjutsu is not however unique to Hyoho Niten Ichi-ryū, nor was nitōjutsu the creation of Musashi. Both Tenshin Shōden Katori Shinto-ryū were founded in the early Muromachi period (ca. 1447), and Tatsumi-ryu founded Eisho period (1504-1520), contain extensive nitōjutsu curricula while also preceding the establishment of Musashi’s Hyoho Niten Ichi-ryū.


Disciplines
Battojutsu
Nitojutsu
Tojutsu
Kojutsu

taijutsu

Taijutsu (体術, Taijutsu? literally "Body Art") is a term for Japanese martial arts techniques that rely solely on body dynamics as opposed to weapons and other devices. 'A truly dynamic, effective and real-life system of self defense and unarmed combat'.

The following description of the intricacies of the art of Taijutsu is taken with permission from the Harukaze Dojo's Website [1]:

" The Japanese term "Taijutsu" is synonymous with the Art of the Ninja. Taijutsu translates as "True technique of the Body." It usually is associated with the Ancient Japanese Empty Hand Techniques practiced by the Ninja and a few other Ancient Martial Ryuha or lineages. The words are easy enough to understand. However, the Art of the Body is not. Notice the name is not "The Art of the Body Parts." It is simply "The Art of the Body." One Completely Unified Body. This concept goes all the way back to the Chinese origins of the Japanese Martial Arts where the Chinese say : "If One Joint Moves, All Nine Joints Move." This is really profound and difficult to understand on the Physical Level. For example, if you tilt your head slightly, just one joint, your neck, will have moved. So, in order to keep your Structural Integrity intact, every other joint in your body will have to shift slightly. If this does not happen, you will lose the Harmony and Balance between your "In" and "Yo" or Yin and Yang. After that, the flow of your Ki or Internal Energy will not be correct and the skill level of your Taijutsu will become much lower. You will have to depend more on local muscle strength and less on whole body power to accomplish your goals. Ki unites your whole body. It is the only one thing that connects the distant parts together. How else can the power from your foot drive your hand? There is no one muscle or even one nerve that travels that whole distance. Yet, with the proper alignment, you can easily feel the power flow from your feet to your finger tips!"


Taijutsu Techniques
Taijutsu techniques may include strikes, kicks, joint locks, throws such as those found in martial arts like jujutsu, judo and karate, etc. While most of its aspects appear external, the student will find many internal aspects as well.

As an example, here's an excerpt from the Bujinkan-Ninpo-Togakure-ryu ninjutsu curriculum:

Taijutsu (body art/movement)
junan taiso (body conditioning)
taihenjutsu (body movement)
ukemi (Receiving the ground safely)
kaiten (rolling)
tobi (leaping)
dakentaijutsu (striking methods)
koppojutsu (bone attacks)
koshijutsu (muscle attacks)
jutaijutsu (grappling methods)
nage (throws)
hajutsu (escapes)
gyakuwaza (locks and controls)
shimewaza (chokes)

ninjutsu

Ninjutsu (忍術, Ninjutsu?) started out as a set of survival skills that were used by groups of people who lived in mountainous regions of Japan They were self-reliant, and had a strong affinity with nature.

The techniques that these mountain folk used to hunt and fight eventually became the strategic base of a new form of martial art ... Ninjutsu. The ninja clans used their art to ensure their survival in a time of violent political turmoil. It also included methods of gathering information, non-detection, avoidance, and misdirection techniques. Ninjutsu can also involve training in disguise, escape, concealment, archery, medicine, and explosives.

Practitioners of ninjutsu have been seen as assassins for hire, and have been associated in the public imagination with other activities which are considered criminal by modern standards. Even though it was influenced by Chinese spying techniques and the strategic principles of Sun Tzu, ninjutsu is believed by its adherents to be of Japanese origin. One version is that the basis of ninjutsu was taught to a Japanese household who fled to the mountains after losing a battle. There they mixed with a varied lot of people including the descendants of refugees who had fled China. Later, the skills were developed over 300 years to create ninjutsu.

Although the popular view is that ninjutsu is the art of secrecy or stealth, actual practitioners consider it to mean the art of enduring - enduring all of life's hardships. The character nin carries both these meanings, and others.

It is true that ninjutsu has a long and myth-filled history, but today almost anyone is allowed to practice modern ninjutsu. As one makes progress in ninjutsu the system gets more sophisticated, and one might realize that the system contains more than fighting skills. To avoid misunderstandings, "ninjutsu" should just refer to a specific branch of Japanese martial arts, unless it is being used in a historical sense.

18 Ninjutsu Skills (Ninja Juhakkei)
The eighteen disciplines were first stated in the scrolls of Togakure-ryū, and they became definitive for all Ninjutsu schools, providing a complete training of the warrior in various fighting arts and complementary disciplines.

However, Ninja Juhakkei was often studied along with Bugei Juhappan (the 18 Samurai fighting art skills). Though some of them are the same, the techniques of each discipline were used with different approaches by both Samurai and Ninja.

The 18 disciplines are:

Seishin-teki kyōyō (spiritual refinement)
Taijutsu (unarmed combat)
Kenjutsu (sword fighting)
Bōjutsu (stick and staff fighting)
Shurikenjutsu (throwing blades)
Sōjutsu (spear fighting)
Naginatajutsu (naginata fighting)
Kusarigamajutsu (chain and sickle weapon)
Kayakujutsu (fire and explosives)
Hensōjutsu (disguise and animal morphing)
Shinobi-iri (stealth and entering methods)
Bajutsu (horsemanship)
Sui-ren (water training)
Bōryaku (military strategy)
Chōhō (espionage)(spying)
Intonjutsu (escaping and concealment)
Tenmon (meteorology and astral projection)
Chi-mon (geography)

Schools of ninjutsu
The Bujinkan Dōjō headed by Masaaki Hatsumi is one of three organizations generally accepted as teaching ninjutsu by the Bujinkan's members (under the name Budo Taijutsu). Hatsumi's Bujinkan Dōjō consists of nine separate schools of allegedly traditional Japanese martial arts, only three of which contain ninjutsu teachings. Hatsumi learned a variety of martial arts, including ninjutsu, from Toshitsugu Takamatsu.

There are two other organizations teaching ninjutsu. These are the Genbukan headed by Shoto Tanemura, who left the Bujinkan in 1984, and the Jinenkan headed by Fumio Manaka, who left later. Both had achieved Menkyo Kaiden before leaving due to differences of opinion with regards to the teaching style.

Other extant traditional martial arts such as the Tenshin Shoden Katori Shintō-ryū contain some aspects of ninjutsu in their curriculum, but are not ninjutsu schools per se.

The espionage techniques of ninjutsu are rarely focused on in recent times, since they serve little purpose to the bulk of modern populations, and tend to attract negative publicity and students with unrealistic expectations.

Another major aspect of authentic ninjitsu training that continues to this day is the wearing of a head dress similar to the islamic hijab. Although in modern times the rules have relaxed somewhat, a ninja can expect sadistic and often inhumane treatment if identified without appropriate ninja dress. The hijab allows the ninja to maintain security of identity (even among friends and relatives), effectively conceal their face from potential enemies and maintain the honour code of the ninja (see also Saving Face).


Other schools
Several other schools of ninjutsu exist, some of which can be traced back to Japanese origins.


Verified Japanese Origins
Israel was one of the first places where Bujinkan ninjutsu was practiced outside Japan, with Doron Navon pioneering it there in 1974. The AKBAN organization uses the Bujinkan curriculum the way it was used when Doron Navon, the first foreign Bujinkan shihan, studied under Hatsumi sensei.

Stephen K. Hayes studied under Masaaki Hatsumi but teaches an Americanized system, To-Shin Do, in his Quest Centers.

Richard Van Donk who was one of the first Foreigners to take the Godan test from Soke Hatsumi in the early 1980s encouraged Hatsumi to do videos of his teachings and helped him distribute them worldwide thereby growing the Ninjutsu art. Richard has been graded to 15th dan from Hatsumi.

The Late Dr. Glenn Morris studied under Masaaki Hatsumi but founded the Hoshin Roshi Ryu.

Chadwick Minge studied under Shoto Tanemura but founded the "Yamato Dojo" ("Studio City Martial Arts") based in California.


Unverified Origins
There are several persons and organizations that teach martial arts which they identify as ninjutsu but who lack a clear lineage to Japanese teachers. While such arts may still be effective, they lack authenticated Japanese lineage.

Ashida Kim is an American martial artist that has made unverified claims of cross training into ninjutsu, as well as unsubstantiated claims of being the last Koga-ryu ninja.
Frank Dux, is a martial artist whose claims of origins are unverified.
Koga-ryu Ninjutsu is believed to have survived into the mid-20th century, apparently having been passed to Fujita Seiko by a relative. Seiko had students, but did not pass on this legacy. Koga-ryu arts are generally considered to be virtually identical to the Iga-ryu arts.

Iaidō

Iaidō
I•ai•dō (居合道), approximately "the art of mental presence and immediate reaction", is a Japanese martial art associated with smooth, controlled movements of drawing the sword from its scabbard or saya, striking or cutting an opponent, removing blood from the blade, and then replacing the sword in the scabbard or saya. Modern day iaidō exponents typically use an iaito for practice. Beginners may use a iaito while the more advanced practicioner might use a shinken (sharpened sword).
Hayashizaki Jinsuke (Minamoto no) Shigenobu is generally credited with establishing the influence and popularity of Iaidō, early in the sixteenth century. However, around a century before his birth, the dynamic art of iaijutsu had been developed by Iizasa Ienao, the founder of the Tensin Shoden Katori Shinto Ryu.
Iaidō should not be confused with kendo (剣道) or kenjutsu (剣術):
• Kendo teaching does not include drawing and re-sheathing of a sword. The weapon used in kendo, a flexible bamboo shinai uses no scabbard. Kendo is practiced with a partner in full contact training or in kata practice.
• Kenjutsu is executed in the form of kata, but usually in pairs, and often does not include drawing or resheathing of the sword,
Delineation from battōjutsu (抜刀術), literally "technique of drawing the sword" is more difficult: battōjutsu is the historical (ca. 15th century) term encompassing both the practice of drawing the sword and cutting (tameshigiri). The term iaijutsu (居合術) became prevalent later (ca. 17th century), and the current term iaidō is due to the general trend of the 1960s to replace -jutsu with -dō in Japanese martial arts in order to emphasize a mental or even spiritual component. In contemporary usage, battōjutsu focuses on the techniques of cutting, with individual practice kata that starts with the sword in the sheath.
Iaidō forms, or kata, are performed individually against one or more imaginary opponents. Some traditional iaidō schools, however, include kata performed in pairs. Some styles and schools also do not practice tameshigiri, cutting techniques.
The primary emphasis in Iaidō, is on the psychological state of being present (居). The secondary emphasis is on drawing the sword and responding to the sudden attack as quickly as possible (合). Starting positions can be from combative postures or from everyday sitting or standing positions. The ability to react quickly from different starting positions was considered essential for a samurai (侍).
A very important part of iai, is nukitsuke or the life of iai. This is a very quick draw accomplished by drawing the sword out of the scabbard by(鞘 saya), moving the saya back in saya biki. The blade may be brought out of the scabbard and used in a quick nukitsuke slashing motion.
History of laido syyles
The Tenshin Shoden Katori Shinto-ryu (天真正伝香取神道流) included iaijutsu (居合術) in its curriculum in 15th century. The first schools dedicated exclusively to sword drawing appeared some time during the late 16th or early 17th century. Most modern schools consider a samurai called Hayashizaki Jinsuke Minamoto no Shigenobu (1546-1621) as the originator of iaidō. Little is known of his life - leading some scholars to doubt his historical existence as a real person. The two largest schools of iaidō that are practised today, Muso Shinden-ryu (夢想神伝流) and Muso Jikiden Eishin-ryu (無雙直傳英信流), and both claim a lineage from Hayashizaki Jinsuke Shigenobu (林崎甚助重信). But to say most, it is a form of Japanese sword art.
Before Nakayama Hakudo (1873?-1958) coined the word iaidō, early in the 20th century, various other names such as battō, battōjutsu, or saya no uchi were used. Iaidō is the usual term to refer to the modern self improvement oriented form taught by the All Japan Kendo Federation (AJKF), while Iaijutsu is used for some amongst the older koryu, combative, techniques.
Seitei Iaidō
Seitei iaidō is the iaidō style of the All Japan Kendo Federation (AJKF, Zen Nippon Kendo Renmei). The AJKF formed in 1956. In 1969, the AJKF introduced the Seitei Gata curriculum of seven kata for iaidō (全日本剣道連盟居合). These were drawn from, or based on, several of the major traditional sword schools, including Muso Jikiden Eishin-ryu, Muso Shinden-ryu and Hoki Ryu. Three more kata were added In 1981, and two more in 2000; increasing the seitei iaidō (seitei gata) curriculum to the current standardised twelve kata for tuition.
These twelve setei gata are now standardised for the tuition, promotion and propagation of iaidō and as a result, seitei iaidō has since become the most widely recognised form of iaidō in Japan and the rest of the world.
Classical Iaidō styles
The two main classical styles (koryu) of iaidō practiced worldwide are Muso Jikiden Eishin-ryu and Muso Shinden-ryu. They resemble each other quite strongly because they branched off from one style sometime in the 18th century, under Oguro Motouemon Kiyakatsu sensei. After Oguro, there came into being two branches that were formed on philosophical differences between two students of Oguro: The Shimomura-ha and Tanimura-ha (branches), the former being headed by Maysuyori Teisuke Hisanari and the latter by Matsuyoshi Teisuke (Shinsuke) Hisanari, who became the 12th grandmaster.
These two branches would co-exist for many years until Muso Jikiden Eishin Ryu officially came into being in the early 20th century through the initiative of Oe Masamichi Shikei, the 17th headmaster of the Jikiden Eishin Ryu. Oe would bring together the Tanimura-ha, Hasegawa Eishin Ryu and the Omori Ryu to form what is today's Muso Jikiden Eishin Ryu.
The Shimomura-ha held its own headmasters and philosophy for many years but would eventually fade away. The last Shimomura-ha (claimed) headmaster, Nakayama Hakudo who is considered the 16th, created a new iai-art called Muso Shinden Battojutsu that was heavily influenced by his Shimomura-ha training, but also took elements from other iai-arts. Nakayama Hakudo is not known to have taught the "pure" Shimomura-ha teachings in its complete form to any of his students and thus it can be argued that Shimomura-ha no longer exists as a separate entity, even though elements of it remain in what would later become the modern Muso Shinden-ryu.
One of the differences between the two schools can be seen in the noto (sheathing the katana back in the saya). In Muso Shinden, noto is done on the horizontal plane, the blade parallel to the floor. In Jikiden, the blade is perpendicular to the floor in a more or less vertical plane.
A third less popular style of iaido is Mugai Ryu Iaido. Mugai ryu is characterized by rapid strong cuts and the almost complete absence of chiburi. It has deep links with zen budhism. Some of the advanced wazas of Mugai ryu also focus on waza that don't kill, but neutralize the opponent. This style has several regional sokes who hold the lineage. Soke Hosho Shiokawa is the 15th soke of Mugai ryu.
There are several branches of Muso Jikiden Eishin-ryū (MJER) that are practised today. Different Iaidō organisations generally recognise different people as their sōke. One person who is considered to be a sōke is Miura Takeyuki Hidefusa, who holds a 9th Dan in MJER. The All Japan Iaidō Federation (Dai Nippon Iaidō Renmei) recognises Ajisai Hirai (9th Dan Hanshi) as the 22nd sōke of MJER.
There are several lines of transmission extant for Muso Shinden-ryu also. One of them claims Mitsuzuka Takeshi as the sōke, second one (those who are affiliated with Nippon Iaidō Kyokai) regard Takada Gakudō as their head teacher.
In the All Japan Kendo Federation (AJKF) or Zen Nippon Kendo Renmei, one of the largest federations both in Japan and outside Japan, there are two lines representing the Muso school. The current sōke for Muso Jikiden Eishin-ryū is Fukui Torao (21st master), and the last sōke for Muso Shinden-ryū was Nakayama Hakudo with no official successor.
Modern Iaijutsu
A newer style of iaijutsu is Toyama-ryu battōjutsu. This is a style originating in the late 19th century, and taught primarily to officers in the Second World War. It is different from the older styles primarily in that all techniques are performed from a standing position. Toyama Ryu was in turn the basis of Nakamura Ryu, created by Nakamura Taizaburo; incorporating Noto and Kamae from older Koryu, notably Omori Ryu. It has been a long time since any differing schools have competed using Shinken (sharp blades); hence it cannot be said that the traditional schools are superior to the modern schools, or vice versa, in the ultimate test.

Bokken

Bokken
A bokken (木剣, bok(u), "wood", and ken, "sword"), is a wooden Japanese sword used for training, usually the size and shape of a katana, but sometimes shaped like other swords. Other common shapes are wakizashi and tantō. They are also known as bokutō (木刀, "wooden sword"), which is also the usual term in Japan.
These should not be confused with shinai, the bamboo sword used in kendo.
Usage
A bokken is used as a relatively safe and inexpensive substitute for a real blade in training for several martial arts. They are used in the early stages of training in iaido, when a practitioner has not yet reached the level where use of an iaito would be safe. An exception occurs when a certain kata involving two people is performed. Then the veteran teacher, or iaidoka, will use a bokken for safety. There are also specially designed bokken made for sword drawing. These are, for the most part, supplied with a plastic or wooden saya and are generally slimmer than a normal bokken and not suited for regular sword techniques.
Kenjutsu makes heavy use of the regular bokken in various drills, as does the Bujinkan and other Ninjutsu systems.
Bokken are used for the practice of kendo; to learn to make proper strokes and get accustomed to the curvature of the blade, as well as to practice the kata (forms). More than a few kata take advantage of the curvature of the blade and the presence of the tsuba, or hand guard, to block the opponent's sword. This is not possible with the straight "blade" of the shinai.
Many Aikido techniques are derived from use of the Japanese sword, although Aikido is primarily an empty-handed art. The focus of the bokken in some aikido dojo is not that of a weapon, but that of a tool to enhance focus. These wooden swords often have a smooth transition between handle and 'blade' and are not used with a tsuba. Other bokken are made to accept a tsuba and have a clearly defined transition between the handle and the 'blade'. Aikidoka practice a form of sword work known as Aiki-Ken that is slightly different from other Japanese arts. The bokken is used in Aiki-Ken to learn proper body placement and distance (maai) from the attacker, in an attempt to be in the safest and most powerful position. Philosophically, Aiki-Ken stresses the importance of moving into the safest killing position, allowing the Aikidoka the option not to perform the killing blow.
Construction
The quality of the bokken depends on several factors. The type of wood used, along with the quality of the wood itself, and the skill of the craftsman, are all critical factors in the manufacture of a good quality bokken. Almost all mass produced inexpensive bokken are made from porous, loose-grained southeast Asian wood. These bokken are easily broken when used in even light to medium contact drills, and are best left to work in kata only. Furthermore, the wood is often so porous, that if the varnish is stripped off the inexpensive bokken, one can see the use of wood fillers to fill the holes.
While most species of North American red oak are unsuitable for construction of bokken, there are some Asian species of red oak that have a significantly tighter grain and will last longer.
Superior woods, such as Japanese white oak, also known as Kashi, has been a proven staple, having a tighter grain than red oak wood. Another choice, hickory wood, seems to have a very good blend of hardness and impact resistance, while still having a relatively low cost.
The use of exotic hardwoods is not unusual when looking at some of the more expensive bokken. Some are made from Brazilian cherrywood (Jatoba), others from purpleheart, and some very expensive ones made from Lignum Vitae. Tropical woods are often quite heavy, a feature often sought in bokken despite the brittleness of these heavy and hard materials. Many of the exotics are suitable for suburi (solo practice), but not for paired practice where there is hard contact with other bokken.
Suburito are bokken designed for suburi. Suburi, literally "bare cutting," are solo cutting exercises. Suburito are thicker and heavier than normal bokken, and users of suburito have to develop both strength and technique. Their weight does, however, tend to make them poorly balanced; consequently, they are usually not used for paired practice or kata.
History
Historically, bokken are as old as Japanese blades, and were used for the training of warriors. Miyamoto Musashi, a legendary kenjutsu master, was infamous for fighting fully armed foes with only one or two bokken. It has been verified that he defeated at least one master swordsman in this manner; Sasaki Kojiro. Kojiro was armed with his "Drying pole", a long nodachi, but Musashi slew him with a bokken he carved from an oar while traveling on a boat to the predetermined island for the duel.

Shinai

A shinai (Japanese: 竹刀) is a practice sword used primarily in Kendo. Shinai are also used in other martial arts, however these are styled differently than kendo shinai, and are represented with different characters.

Construction
The Shinai is made of four bamboo slats (take) held together by two pieces of leather, tsuka-gawa (handle) and saki-gawa (tip), and a string (tsuru). Placed under the saki-gawa is a plastic plug saki-gomu. To prevent the four take from getting misplaced there is a small square of metal, chigiri, placed between them inside the tsuka-gawa. A leather thong (nakayui) is wrapped around the take and tied to the tsuru about one-third of the way down the shinai from the tip (kensen); this holds take together in the event of a break and marks the proper striking portion of the blade (datosubu). Shinai are available in many styles and balances, and some may be treated (smoked or resin soaked) or made from carbon fiber alternative materials.

Care of Shinai
A Shinai must be properly taken care of or it can pose a danger to both the user, and the people around it. Shinai should be inspected for splinters and breaks before and after use, and taken care of in the manner considered most appropriate by one's style, dojo, or sensei.

Many people believe that oiling and sanding a shinai prior to use, and periodically during use can greatly extend its life. However, even in Japan, people disagree on what is considered proper shinai care and there is much lore and myth surrounding various methods.

To properly inspect a shinai, one first examines the area around the datosubu, looking on all sides of the shinai for splinters. Bamboo splinters infect easily, so care should be taken by either using a glove or rag while sanding the splinters down. The saki-gawa should be intact and the tsuru should be tight so that the saki-gawa cannot slip off the end of the shinai while in use. In addition, the nakayui should be tight enough as to not rotate easily.

Regulations
In competition there are regulated weights and lengths of the Shinai.

Adult females: maximum length 120 cm, weight minimum 440 grams
Adult males: maximum length 120 cm, weight minimum 510 grams.

Trivia
Like many weapons, it can also be used as an implement for corporal punishment, notably in spanking, more common in Japan than the paddle in the US.
The Shinai has become a popular tool/weapon in Professional wrestling, due to its intimidating look and the loud cracking sound it makes once it strikes someone. It is frequently called Singapore Cane or Kendo Stick by the less knowledgeable. It is especially identified with the professional wrestler The Sandman. It was also identified with wrestlers Steve Blackman, Tommy Dreamer, and Justin Credible, as well as wrestling executive Shane McMahon during his occasional appearances as a wrestler.
In manga, Rurouni Kenshin by Nobuhiro Watsuki, Myojin Yahiko uses a shinai.

KENDO

Kendo

Kendo (剣道, Kendō?) or "way of the sword", is the martial art of Japanese fencing.

Kendo developed from traditional techniques of Japanese swordsmanship known as kenjutsu.

The Dai Nippon Butoku Kai, was established in 1895 to solidify, promote, and standardise all martial disciplines and systems in Japan. The DNBK, changed the name of Gekiken (Kyūjitai: 擊劍; Shinjitai: 撃剣, "hitting sword") to kendo in 1920.

In 1975 the All Japan Kendo Federation (AJKF), developed an explanation of the concept and purpose of studying kendo.

The Concept of Kendo is to discipline the human character through the application of the principles of the katana.

The Purpose of practicing Kendo is:

To mold the mind and body,
To cultivate a vigorous spirit,
And through correct and rigid training,
To strive for improvement in the art of Kendo,
To hold in esteem human courtesy and honor,
To associate with others with sincerity,
And to forever pursue the cultivation of oneself.
This will make one be able:
To love his/her country and society,
To contribute to the development of culture
And to promote peace and prosperity among all peoples.

Kendo is a physically and mentally challenging activity that combines strong martial arts values with sporting-like physical elements. Kendo embodies the essence of Japanese fighting arts.

Practitioners of kendo are called kendoka (one who practices kendo) or kenshi (swordsman). The latter may also be applied to practitioners of other traditional Japanese sword arts. Around 8 million people world-wide practice kendo with approximately 7 million of them in Japan.

Equipment and costume
Kendo is practiced using "swords" made of split bamboo called shinai and extensive protective armour (bogu) is worn to protect specified target areas on the head and body. Kendoka also use bokken|bokuto (wooden swords) to practice set forms known as kata. The costume, worn under the bogu comprises a jacket, or kendogi/keikogi and a hakama, which is a garment with wide legs.

Kendo is ideally practiced in a purpose-built dojo, though standard sports halls and other venues are often used instead. An appropriate venue has a clean and well-sprung wooden floor, allowing safe use of Kendo's distinctive stamping footwork for the bare-footed practitioners.

History
Since the earliest samurai government in Japan, during the Kamakura period (1185-1233), sword fencing, together with horse riding and archery, were the main martial pursuits of the military clans. In this period kendo developed under the strong influence of Zen Buddhism. The samurai could equate the disregard for his own life in the heat of battle, which was considered necessary for victory in individual combat, to the Buddhist concept of the illusory nature of the distinction between life and death.


Kendō at an agricultural school in Japan around 1920Those swordsmen established schools of kendo training which continued for centuries, and which form the basis of kendo practice today. The names of the schools reflect the essence of the originator’s enlightenment. Thus the Itto-Ryu (Single sword school) indicates the founder’s illumination that all possible cuts with the sword emanate from and are contained in one original essential cut. The Muto (swordless school) expresses the comprehension of the originator Yamaoka Tesshu, that "There is no sword outside the mind". The 'Munen Muso Ryu’ (No Intent, no preconception) similarly expresses the understanding that the essence of Kendo transcends the reflective thought process.

The formal kendo exercises developed several centuries ago, are still studied today using wooden swords in set forms, or kata. Kendo teaching emphasise a co-ordinated whole body movement.

The introduction of bamboo practice swords (shinai) and armour (bogu) to kendo training is attributed to Naganuma Sirozaemon Kunisato (長沼四郎左衛門国郷 1688-1767). This is believed to be the foundation of modern kendo.

Kendo began to make its modern appearance during the late 18th century. Use of the shinai and armour (bogu) made possible the full force delivery of strikes and thrusts without inflicting injury on the opponent. These advances, along with practice formats, set the foundations of modern kendo.

Concepts such as 'mushin', or 'empty mind' as professed by exponents of Zen, are an essential attainment for high level kendo. Fudoshin, or 'unmoving mind', is a conceptual attribute of the deity Fudo Myo-O, one of the five 'Kings of Light' of Shingon Buddhism. Fudoshin, implies that the kendoka cannot be led astray by delusions of anger, doubt, fear, or surprise arising from the opponent’s actions. Thus today it is possible to embark on a similar quest for spiritual enlightenment as followed by the samurai of old.

Modern kendo
In modern kendo, there are strikes (or cuts) and thrusts. Strikes are allowed against only seven specified target areas, or datotsu-bui on the head or body, all of which are protected by bogu. The targets are men (top of the head), sayu-men or yoko-men (upper left and right side of the head), the right kote, or wrist at any time, the left kote when it is in a raised position (such as jodan) and the left or right do or torso. Thrusts are only allowed to the throat (tsuki). However, since an incorrectly performed thrust could injure the neck, thrusting techniques in free practice and competition are often restricted to senior dan graded kendoka.

Competition
In shiai, or competition, a point is only awarded when the attack is made firmly and properly to a target point with ki-ken-tai-ichi, or spirit, sword and body as one. This means that for an attack to be successful, the shinai must strike the specified target, the contact by the shinai must happen simultaneously with the attacker's front foot contacting with floor and the kendoka must vocalise an expression of kiai that displays good spirit. Additionally, the top third of the shinai must make contact with the target and direction of movement by the shinai must also be correct. Finally, zanshin, or continuation of awareness, must be present and shown before, during and after the strike, then the player must be ready to attack again.

In a tournament, there are usually three referees, or shinpan. Each holds a red flag and a white flag in opposite hands. To signal a point, the shinpan raise the flag corresponding to the colour of the ribbon worn by the scoring competitor. Generally, at least two shinpan must agree, for a point to be awarded. The match continues until a pronouncement of the point that has been scored.

The first competitor to score two points wins the match. If the time limit is reached and only one competitor has a point, that competitor wins.

In the case of a tie, there are several options:

The match may be declared a draw.
The match may be extended (encho), and the first competitor to score a point wins.
The winner may be chosen by a decision made by the shinpan, or hantei, in which the three referees vote for their choice. This is done simultaneously, by show of flags.

Grades
Technical achievement in kendo is measured by advancement in grade, rank or level. The "kyu" and "dan" grading system is used to assess the level of one's skill in kendo. The dan levels are from 1-dan (sho-dan) to 10-dan (ju-dan). There are usually 6 grades below 1-dan known as kyu. The kyu numbering is in reverse order with 1-kyu (ikkyu) being the grade immediately below 1-dan.

In the AJKF the grades of 9-dan (kyu-dan) and 10-dan (ju-dan) are no longer awarded. However, FIK grading rules allow national kendo organisations to establish a special committee to consider the award of those grades.

There are no visible differences between kendo grades; beginners may dress the same as higher-ranking yudansha.

All candidates for examination face a panel of examiners. A larger, more qualified panel is usually assembled to assess the higher dan grades.

Kendo examinations typically consist of a demonstration of the applicants skill and for some dan grades, also a written exam. The 8-dan kendo exam is extremely difficult, with a reported pass rate of less than 1 percent.

Kata
There are 10 nihon kendo kata (Japanese kendo forms). These are performed with wooden swords (bokken/bokuto), the kata include fundamental techniques of attacking and counter-attacking, and have useful practical application in general kendo. Occasionally, real swords or swords with a blunt edge, called kata-yo or habiki, may be used for a display of kata.

Kata 1–7 are performed with both partners using a bokken (long sword) of around 102 cm. Kata 8–10 are performed with one partner using a bokken and the other using a kodachi (short sword) of around 55cm.

During kata practice, the participants take the roles of either uchidachi (teacher) or shidachi (student). The uchidachi makes the first move or attack in each kata. As this is a teaching role, the uchidachi is always the 'losing' side, thus allowing the shidachi or student to learn and gain confidence.

Nihon kendo kata were drawn from representative kenjutsu schools and tend to be quite deep and advanced. In some areas the regular training curriculum does not include nihon kendo kata.

In 2003, the introduction of Bokuto Ni Yoru Kendo Kihon-waza Keiko-ho, a set of basic exercises using a (bokken/bokuto), attempted to bridge this gap. Bokuto Ni Yoru Kendo Kihon-waza Keiko-ho is intended primarily for kendoka up to 2-dan, but is useful for all kendo students.

Japanese (日本語, Nihongo (help·info)) is a language spoken by over 130 million people, mainly in Japan, but also by Japanese emigrant communities around the world. It is an agglutinative language and is distinguished by a complex system of honorifics reflecting the hierarchical nature of Japanese society, with verb forms and particular vocabulary to indicate the relative status of speaker, listener and the person mentioned in conversation. The sound inventory of Japanese is relatively small, and has a lexically distinct pitch-accent system. Early Japanese is known largely on the basis of its state in the 8th century, when the three major works of Old Japanese were compiled, but smaller amounts of material, primarily inscriptional, is of earlier date. The earliest attestation of Japanese is in a Chinese document from 252 C.E.

The Japanese language is written with a combination of three different types of glyphs: Chinese characters, kanji, and two syllabic scripts, hiragana and katakana. The Latin alphabet, rōmaji, is also often used in modern Japanese, especially for company names and logos, advertising, and when inputting Japanese into a computer. Western style Arabic numerals are generally used for numbers, but traditional Sino-Japanese numeral are also commonplace.

Japanese vocabulary has been heavily influenced by loans from other languages. A vast number of words were borrowed from Chinese, or created from Chinese models, over a period of at least 1,500 years. Since the late 19th century, Japanese has borrowed a considerable number of words from Indo-European languages, primarily English. Because of the special trade relationship between Japan and Holland in the 17th century, Dutch has also been influential, with words like bīru (from bier; "beer") and kōhī (from koffie; "coffee") being of Dutch origin.

classification

Historical linguists who specialize in Japanese agree that it is one of the two members of the Japonic language family, the other member being Ryūkyūan. (An older view, still held by many non-specialists, is that Japanese is a language isolate, of which the Ryūkyūan languages are dialects.)

The genetic affiliation of the Japonic family is uncertain. Numerous theories have been proposed, relating it to a wide variety of other languages and families, including extinct languages spoken by historic cultures of the Korean peninsula; the Korean language; the Altaic languages; and the Austronesian languages, among many others. It is also often suggested that it may be a creole language combining more than one of these. The various theories are detailed in the main article. At this point, no one theory is generally accepted as correct, and the issue is likely to remain controversial.

Geographic distribution
Although Japanese is spoken almost exclusively in Japan, it has been and is still sometimes spoken elsewhere. When Japan occupied Korea, Taiwan, parts of the Chinese mainland, and various Pacific islands during and before World War II, locals in those countries were forced to learn Japanese in empire-building programs. As a result, there are still many people in these countries who speak Japanese instead of, or in addition to, the local languages. Japanese emigrant communities (the largest of which are to be found in Brazil) frequently employ Japanese as their primary language. Japanese emigrants can also be found in Peru, Australia (especially Sydney, Brisbane, and Melbourne), and the United States (notably California and Hawaii). There is also a small emigrant community in Davao, Philippines. Their descendants (known as nikkei 日系, literally Japanese descendants), however, rarely speak Japanese fluently. There are estimated to be several million non-Japanese studying the language as well; many schools, both primary and secondary, offer courses.

Official status
Japanese is the de facto official language of Japan, which is the only country to have Japanese as an official working language. There are two forms of the language considered standard: hyōjungo (標準語, hyōjungo?) or standard Japanese, and kyōtsūgo (共通語, kyōtsūgo?) or the common language. As government policy has modernized Japanese, many of the distinctions between the two have blurred. Hyōjungo is taught in schools and used on television and in official communications, and is the version of Japanese discussed in this article.

Standard Japanese can also be divided into bungo (文語, bungo?) or "literary language," and kōgo (口語, kōgo?) or "oral language", which have different rules of grammar and some variance in vocabulary. Bungo was the main method of writing Japanese until the late 1940s, and still has relevance for historians, literary scholars, and lawyers (many Japanese laws that survived World War II are still written in bungo, although there are ongoing efforts to modernize their language). Kōgo is the predominant method of speaking and writing Japanese today, although bungo grammar and vocabulary are occasionally used in modern Japanese for effect.

Dialects
Dozens of dialects are spoken in Japan. The profusion is due to many factors, including the length of time the archipelago has been inhabited, its mountainous island terrain, and Japan's long history of both external and internal isolation. Dialects typically differ in terms of pitch accent, inflectional morphology, vocabulary, and particle usage. Some even differ in vowel and consonant inventories, although this is uncommon.

The main distinction in Japanese dialects is between Tokyo-type (東京式, Tōkyō-shiki?) and Western-type (京阪式, Keihan-shiki?), though Kyūshū-type dialects form a smaller third group. Within each type are several subdivisions. The Western-type dialects are actually in the central region, with borders roughly formed by Toyama, Kyōto, Hyōgo, and Mie Prefectures; most Shikoku dialects are also Western-type. Dialects further west are actually of the Tokyo type. The final category of dialects are those that are descended from the Eastern dialect of Old Japanese; these dialects are spoken in Hachijojima, Tosa, and very few other locations.

Dialects from peripheral regions, such as Tōhoku or Tsushima, may be unintelligible to speakers from other parts of the country. The several dialects used in Kagoshima in southern Kyūshū are famous for being unintelligible not only to speakers of standard Japanese but to speakers of nearby dialects elsewhere in Kyūshū as well, probably due in part to the Kagoshima dialects' peculiarities of pronunciation, which include the existence of closed syllables (i.e., syllables that end in a consonant, such as /kob/ or /koʔ/ for Standard Japanese /kumo/ "spider"). The vocabulary of Kagoshima dialect is 84% cognate with standard Tokyo dialect. Kansai-ben, a group of dialects from west-central Japan, is spoken by many Japanese; the Osaka dialect in particular is associated with comedy.

The Ryūkyūan languages, while closely related to Japanese, are distinct enough to be considered a separate branch of the Japonic family, and are not dialects of Japanese. They are spoken in the Ryūkyū Islands and in some islands that are politically part of Kagoshima Prefecture. Not only is each language unintelligible to Japanese speakers, but most are unintelligible to those who speak other Ryūkyūan languages.

Recently, Standard Japanese has become prevalent nationwide (including portions of the Ryūkyūan islands like Okinawa) due not only to television and radio, but also to increased mobility within Japan due to its system of roads, railways, and airports. Young people usually speak their local dialect and the standard language, though in most cases, the local dialect is influenced by the standard, and regional versions of "standard" Japanese have local-dialect influence.

sounds

Japanese vowels are "pure" sounds, similar to their Spanish, Greek or Italian counterparts. The only unusual vowel is the high back vowel /ɯ/, which is like /u/, but compressed instead of rounded. Japanese has five vowels, and vowel length is phonemic, so each one has both a short and a long version.

Some Japanese consonants have several allophones, which may give the impression of a larger inventory of sounds. However, some of these allophones have since become phonemic. For example, in the Japanese up to and including the first half of the twentieth century, the phonemic sequence /ti/ was palatalized and realized phonetically as [tɕi], approximately chi; however, now /ti/ and /tɕi/ are distinct, as evidenced by words like paatii [paatii] "party" and chi [tɕi] "ground."

The r of the Japanese language (technically a lateral apical postalveolar flap), is of particular interest, sounding to most Europeans' ears to be something between an l and a retroflex r depending on its position in a word.

The syllabic structure and the phonotactics are very simple: the only consonant clusters allowed within a syllable consist of one of a subset of the consonants plus /j/. This type of clusters only occurs in onsets. However, consonant clusters across syllables are allowed as long as the two consonants are a nasal followed a homo-organic consonant. The consonant length (geminates) is also phonemic.

Grammer

Sentence structure
The basic Japanese word order is Subject Object Verb. Subject, Object, and other grammatical relations are usually marked by particles, which are suffixed to the words that they modify, and are thus properly called postpositions.

The basic sentence structure is topic-comment. For example, Kochira-wa Tanaka-san desu. Kochira ("this") is the topic of the sentence, indicated by the particle -wa. The verb is desu, a copula, commonly translated as "to be" (though there are other verbs that can be translated as "to be"). As a phrase, Tanaka-san desu is the comment. This sentence loosely translates to "As for this person, (it) is Mr./Mrs./Ms. Tanaka." Thus Japanese, like Chinese, Korean, and many other Asian languages, is often called a topic-prominent language, which means it has a strong tendency to indicate the topic separately from the subject, and the two do not always coincide. The sentence Zō-wa hana-ga nagai (desu) literally means, "As for elephants, (their) noses are long". The topic is zō "elephant", and the subject is hana "nose".

Japanese is a pro-drop language, meaning that the subject or object of a sentence need not be stated if it is obvious from context. In addition, it is commonly felt that the shorter a Japanese sentence is, the better (a quality called "iki" in Japanese). As a result of this grammatical permissiveness and tendency towards brevity, Japanese speakers tend naturally to omit words from sentences, rather than refer to them with pronouns. In the context of the above example, hana-ga nagai would mean "[their] noses are long," while nagai by itself would mean "[they] are long." A single verb can be a complete sentence: Yatta! "[I / we / they / etc] did [it]!". In addition, since adjectives can form the predicate in a Japanese sentence (below), a single adjective can be a complete sentence: Urayamashii! "[I'm] jealous [of it]!".

While the language has some words that are translated as pronouns, these are not used as frequently as pronouns in some Indo-European languages, and function differently. Instead, Japanese typically relies on special verb forms and auxiliary verbs to indicate the "direction" of an action: "down" to the speaker or persons related to the speaker, or "up" to the listener or other person. For example, setsumei shite moratta (literally, "[I/we] obtained explaining") means "[he/she] explained it to [me/us]". Similarly, oshiete ageta (literally, "teach-handed up") is commonly used to mean "[I/we] told [him/her]". Such "directional" auxiliary verbs thus serve a function comparable to that of pronouns and prepositions in Indo-European languages to indicate the actor and the recipient of an action.

Japanese "pronouns" also function differently from most modern Indo-European pronouns (and more like nouns) in that they can take modifiers as any other noun may. For instance, one cannot say in English:

*The big he ran down the street. (ungrammatical)
But one can grammatically say essentially the same thing in Japanese:

Ōkii kare-wa michi-o hashitte itta. (grammatically correct)
This is partly due to the fact that these words evolved from regular nouns, such as kimi "you" (君 "lord"), anata "you" (貴方 "that side, yonder" or 貴女 "that woman"), and boku "I" (僕 "servant"). This is why some linguists do not classify Japanese "pronouns" as pronouns, but rather as referential nouns. Japanese personal pronouns are generally used only in situations requiring special emphasis as to who is doing what to whom.

The choice of words used as pronouns is correlated with the sex of the speaker and the social situation in which they are spoken: men and women alike in a formal situation generally refer to themselves as watashi (私 "private") or watakushi (also 私), while men in rougher or intimate conversation are much more likely to use the word ore (俺 "we", "myself") or boku. Similarly, different words such as anata, kimi, and omae (お前, more formally 御前 "the one before me") may be used to refer to a listener depending on the listener's relative social position and the degree of familiarity between the speaker and the listener. When used in different social relationships, the same word may have positive (intimate or respectful) or negative (distant or disrespectful) connotations.

Japanese often use titles of the person referred to where pronouns would be used in English. For example, when speaking to one's teacher, it is appropriate to use sensei (先生, teacher), but inappropriate to use anata. This is because anata is used to refer to people of equal or lower status, and one's teacher has higher status.

It is very common for English speakers to include watashi-wa or anata-wa at the beginning of every Japanese sentence. Though these sentences are grammatically correct, they sound terribly strange even in very formal situations. It is roughly the equivalent of using a noun over and over in English, when a pronoun would suffice: "John is coming over, so make sure you fix John a sandwich, because John loves sandwiches. I hope John likes the dress I'm wearing..."

Inflection and conjugation
Japanese has no grammatical number or gender. The noun hon (本) may refer to a single book or several books; hito (人) can mean "person" or "people"; and ki (木) can be "tree" or "trees". Where number is important, it can be indicated by providing a quantity (often with a counter word) or (rarely) by adding a suffix. Words for people are usually understood as singular. Thus Tanaka-san usually means Mr./Ms. Tanaka. Words that refer to people and animals can be made to indicate a group of individuals through the addition of a collective suffix (a noun suffix that indicates a group), such as -tachi, but this is not a true plural: the meaning is closer to the English phrase "and company". A group described as Tanaka-san-tachi may include people not named Tanaka. Some Japanese nouns are effectively plural, such as hitobito "people" and wareware "we/us", but these are sporadic and irregular.

Verbs are conjugated to show tenses, of which there are two: past and present, or non-past, which is used for the present and the future. For verbs that represent an ongoing process, the -te iru form indicates a continuous (or progressive) tense. For others that represent a change of state, the -te iru form indicates a perfect tense. For example, kite iru means "He has come (and is still here)", but tabete iru means "He is eating".

Questions (both with an interrogative pronoun and yes/no questions) have the same structure as affirmative sentences, but with intonation rising at the end. In the formal register, the question particle -ka is added. For example, Ii desu "It is OK" becomes Ii desu-ka "Is it OK?". In a more informal tone sometimes the particle -no is added instead to show a personal interest of the speaker: Dōshite konai-no? "Why aren't (you) coming?". Some simple queries are formed simply by mentioning the topic with an interrogative intonation to call for the hearer's attention: Kore-wa? "(What about) this?"; Namae-wa? "(What's your) name?".

Negatives are formed by inflecting the verb. For example, Pan-o taberu "I will eat bread" or "I eat bread" becomes Pan-o tabenai "I will not eat bread" or "I do not eat bread".

The so-called -te verb form is used for a variety of purposes: either progressive or perfect aspect (see above); combining verbs in a temporal sequence (Asagohan-o tabete sugu dekakeru "I'll eat breakfast and leave at once"), simple commands, conditional statements and permissions (Dekakete-mo ii? "May I go out?"), etc.

The word da (plain), desu (polite) is the copula verb. It corresponds approximately to the English be, but often takes on other roles. Two additional common verbs are used to indicate existence ("there is") or, in some contexts, property: aru (negative nai) and iru (negative inai), for inanimate and animate things, respectively. For example, Neko ga iru "There's a cat", Ii kangae-ga nai "[I] haven't got a good idea".

The verb "to do" (suru, polite form shimasu) is often used to make verbs from nouns (ryōri suru "to cook", benkyō suru "to study", etc.) and has been productive in creating modern slang words. Japanese also has a huge number of compound verbs to express concepts that are described in English using a verb and a preposition (e.g. tobidasu "to fly out, to flee," from tobu "to fly, to jump" + dasu "to put out, to emit").

There are three types of adjective (see also Japanese adjectives):

keiyōshi, or i adjectives, which have a conjugating ending i (such as atsui, "to be hot") which can become past (atsukatta - "it was hot"), or negative (atsuku nai - "it is not hot"). Note that nai is also an i adjective, which can become past (atsuku nakatta - it was not hot).
atsui hi "a hot day".
keiyōdōshi, or na adjectives, which are followed by a form of the copula, usually na. For example hen (strange)
hen na hito "a strange person".
rentaishi, also called true adjectives, such as onaji "the same"
onaji hi "the same day".
Both keiyōshi and keiyōdōshi may predicate sentences. For example,

Gohan-ga atsui. "The rice is hot."
Kare-wa hen da. "He's strange."
Both inflect, though they do not show the full range of conjugation found in true verbs. The rentaishi in Modern Japanese are few in number, and unlike the other words, are limited to directly modifying nouns. They never predicate sentences. Examples include ookina "big" and onaji "the same" (although there is also a noun onaji that can be followed by da, as in onaji da).

Both keiyōdōshi and keiyōshi form adverbs, by following with ni in the case of keiyōdōshi:

hen ni naru "become strange",
and by changing i to ku in the case of keiyōshi:

atsuku naru "become hot".
The grammatical function of nouns is indicated by postpositions, also called particles. These include for example:

ga for the nominative case. Not necessarily a subject.
Kare ga yatta. "He did it."
ni for the dative case.
Tanaka-san ni kiite kudasai "Please ask Mr. Tanaka."
no for the genitive case, or nominalizing phrases.
watashi no kamera "my camera"
Sukī-ni iku no ga suki desu "(I) like going skiing."
o for the accusative case. Not necessarily an object.
Nani o tabemasu ka? "What will (you) eat?"
wa for the topic. It can co-exist with case markers above except no, and it overrides ga and o.
Watashi wa tai-ryōri ga ii desu. "As for me, Thai food is good." The nominative marker ga after watashi is hidden under wa. (Note that English generally makes no distinction between sentence topic and subject.)
Note: The difference between wa and ga goes beyond the English distinction between sentence topic and subject. While wa indicates the topic, which the rest of the sentence describes or acts upon, it carries the implication that the subject indicated by wa is not unique, or may be part of a larger group.

Ikeda-san wa yonjū-ni sai da. "As for Mr. Ikeda, he is forty-two years old." Others in the group may also be of that age.
Absence of wa often means the subject is the focus of the sentence.

Ikeda-san ga yonjū-ni sai da. "It is Mr. Ikeda who is forty-two years old." This is a reply to an implicit or explicit question who in this group is forty-two years old.

Politeness

Unlike most western languages, Japanese has an extensive grammatical system to express politeness and formality.

Broadly speaking, there are three main politeness levels in spoken Japanese: the plain form (futsūgo 普通語), the simple polite form (teineigo 丁寧語) and the advanced polite form (keigo 敬語).

Since most relationships are not equal in Japanese society, one person typically has a higher position. This position is determined by a variety of factors including job, age, experience, or even psychological state (e.g., a person asking a favour tends to do so politely). The person in the lower position is expected to use a polite form of speech, whereas the other might use a more plain form. Strangers will also speak to each other politely. Japanese children rarely use polite speech until they are teens, at which point they are expected to begin speaking in a more adult manner. See uchi-soto

The plain form in Japanese is recognized by the shorter, dictionary form of verbs, and the da form of the copula. At the teinei level, verbs end with the helping verb -masu, and the copula desu is used. The advanced polite form, keigo, actually consists of two kinds of politeness: honorific language (sonkeigo 尊敬語) and humble (kenjōgo 謙譲語) language. Whereas teineigo is an inflectional system, keigo often employs many special honorific and humble verb forms: iku "to go" becomes ikimasu in polite form, but is replaced by mairimasu in humble speech and irasshaimasu in honorific speech.

The difference between honorific and humble speech is particularly pronounced in the Japanese language. Humble language is used to talk about oneself or one's own group (company, family) whilst honorific language is mostly used when describing the interlocutor and his/her group. For example, the -san suffix ("Mr" or "Ms") is an example of honorific language. It is not used to talk about oneself or when talking about someone from one's company to an external person, since the company is the speaker's "group". When speaking directly to one's superior in one's company or when speaking with other employees within one's company about a superior, a Japanese person will use vocabulary and inflections of the honorific register to refer to the in-group superior and his or her speech and actions. When speaking to a person from another company (i.e., a member of an out-group), however, a Japanese person will use the plain or the humble register to refer to the speech and actions of his or her own in-group superiors. In short, the register used in Japanese to refer to the person, speech, or actions of any particular individual varies depending on the relationship (either in-group or out-group) between the speaker and listener, as well as depending on the relative status of the speaker, listener, and third-person referents. For this reason, the Japanese system for explicit indication of social register is known as a system of "relative honorifics." This stands in stark contrast to the Korean system of "absolute honorifics," in which the same register is used to refer to a particular individual (e.g. one's father, one's company president, etc.) in any context regardless of the relationship between the speaker and interlocutor. Thus, polite Korean speech can sound very presumptuous when translated verbatim into Japanese, as in Korean it is acceptable and normal to say things like "Our Mr. Company-President..." when communicating with a member of an out-group, which would be very inappropriate in a Japanese social context.

Most nouns in the Japanese language may be made polite by the addition of o- or go- as a prefix. o- is generally used for words of native Japanese origin, whereas go- is affixed to words of Chinese derivation. In some cases, the prefix has become a fixed part of the word, and is included even in regular speech, such as gohan 'cooked rice; meal.' Such a construction often indicates deference to either the item's owner or to the object itself. For example, the word tomodachi 'friend,' would become o-tomodachi when referring to the friend of someone of higher status (though mothers often use this form to refer to their children's friends). On the other hand, a polite female speaker may sometimes refer to mizu 'water' as o-mizu merely to show politeness; this contrasts with the more abrupt speech of rude men (though men may also use very polite forms when speaking to superiors). See Gender differences in spoken Japanese.

Most Japanese people employ politeness to indicate a lack of familiarity. That is, they use polite forms for new acquaintances, but if a relationship becomes more intimate, they no longer use them. This occurs regardless of age, social class, or gender.

Many researchers report[citation needed] that since the 1990s, the use of polite forms has become rarer. Needless to say, many older people disapprove of this trend. Young people usually receive extensive training in the "proper" use of polite language when they start to work for a company.

Vocabulary

The original language of Japan, or at least the original language of a certain population that was ancestral to a significant portion of the historical and present Japanese nation, was the so-called yamato kotoba (大和言葉 or 大和詞, i.e. "Yamato words"）, which in scholarly contexts is sometimes referred to as wa-go (倭語 or 和語, i.e. the "Wa language"). In addition to words from this original language, present-day Japanese includes a great number of words that were either borrowed from Chinese or constructed from Chinese roots following Chinese patterns. These words, known as kango, entered the language from the fifth century onwards via contact with Chinese culture, both directly and through the Korean peninsula. According to some estimates, Chinese-based words comprise as much as seventy percent of the total vocabulary of the modern Japanese language and form as much as thirty to forty percent of words used in speech.

Like Latin-derived words in English, kango words typically are perceived as somewhat formal or academic compared to equivalent Yamato words. Indeed, it is generally fair to say that an English word derived from Latin/French roots typically corresponds to a Sino-Japanese word in Japanese, whereas a simpler Anglo-Saxon word would best be translated by a Yamato equivalent.

A much smaller number of words has been borrowed from Korean and Ainu. Japan has also borrowed a number of words from other languages, particularly ones of European extraction, which are called gairaigo. This began with borrowings from Portuguese in the 16th century, followed by borrowing from Dutch during Japan's long isolation of the Edo period. With the Meiji Restoration and the reopening of Japan in the 19th century, borrowing occurred from German, French and English. Currently, words of English origin are the most commonly borrowed.

In the Meiji era, the Japanese also coined many neologisms using Chinese roots and morphology to translate Western concepts. The Chinese and Koreans imported many of these pseudo-Chinese words into Chinese, Korean, and Vietnamese via their kanji characters in the late 19th and early 20th centuries. For example, 政治 seiji ("politics"), and 化学 kagaku ("chemistry") are words derived from Chinese roots that were first created and used by the Japanese, and only later borrowed into Chinese and other East Asian languages. As a result, Japanese, Chinese, Korean, and Vietnamese share a large common corpus of vocabulary in the same way a large number of Greek- and Latin-derived words are shared among modern European languages, although many academic words formed from such roots were certainly coined by native speakers of other languages, such as English.

In the past few decades, wasei-eigo (made-in-Japan English) has become a prominent phenomenon. Words such as wanpataan (<>

Before the 5th century, the Japanese had no writing system of their own. They began to adopt the Chinese writing script along with many other aspects of Chinese culture after their introduction by Korean monks and scholars during the 5th and 6th centuries AD.


The table of KanaAt first, the Japanese wrote in Classical Chinese, with Japanese names represented by characters used for their meanings and not their sounds. Later, this latter principle was used to write pure Japanese poetry and prose; however, some Japanese words were written with characters for their meaning and not the original Chinese sound. An example of this mixed style is the Kojiki, which was written in 712 AD. They then started to use Chinese characters to write Japanese in a style known as man'yōgana, a syllabic script which used Chinese characters for their sounds in order to transcribe the words of Japanese speech syllable by syllable.

Over time, a writing system evolved. Chinese characters (kanji) were used to write either words borrowed from Chinese, or Japanese words with the same or similar meanings. Chinese characters were also used to write grammatical elements, were simplified, and eventually became two syllabic scripts: hiragana and katakana.

Modern Japanese is written in a mixture of three main systems: kanji, characters of Chinese origin used to represent both Chinese loanwords into Japanese and a number of native Japanese morphemes; and two syllabaries: hiragana and katakana. The Latin alphabet is also sometimes used. Arabic numerals are much more common than the kanji characters when used in counting, but kanji numerals are still used in compounds, such as 統一 tōitsu ("unification").

Hiragana are used for words without kanji representation, for words no longer written in kanji, and also following kanji to show conjugational endings. Because of the way verbs (and adjectives) in Japanese are conjugated, kanji alone cannot fully convey Japanese tense and mood, as kanji cannot be subject to variation when written without losing its meaning. For this reason, hiragana are suffixed to the ends of kanji to show verb and adjective conjugations. Hiragana used in this way are called okurigana. Hiragana are also written in a superscript called furigana above or beside a kanji to show the proper reading. This is done to facilitate learning, as well as to clarify particularly old or obscure (or sometimes invented) readings.

Katakana, like hiragana, are a syllabary; katakana are primarily used to write foreign words, plant and animal names, and for emphasis. For example "Australia" has been adapted as Ōsutoraria, and "supermarket" has been adapted and shortened into sūpā. Rōmaji (ローマ字), literally "Roman letters," is the Japanese term for the Latin alphabet. Rōmaji are used for some loan words like "CD", "DVD", etc., and also for some Japanese creations like "Sony."

Japanese students begin to learn kanji characters from their first year at elementary school. A guideline created by the Japanese Ministry of Education, the list of kyōiku kanji, specifies the 1,006 simple characters a child is to learn by the end of sixth grade. Children continue to study another 939 characters in junior high school, covering in total 1,945 jōyō kanji ("common use kanji") characters, which is generally considered sufficient for everyday life, although many kanji used in everyday life are not included in the list. An appendix of 290 additional characters for names was decreed in 1951. Various semi-official bodies were set up to monitor and enforce restrictions on the use of kanji in the press, publishing, in television broadcasts, etc. Thereafter, the official list of kyōiku kanji was repeatedly revised, but the total number of officially sanctioned characters remained largely unchanged.

A different list of officially approved kanji is used for purposes of registering personal names. Names containing unapproved characters are denied registration. However, as with the list of kyōiku kanji, criteria for inclusion were often arbitrary and led to many common and popular characters being disapproved for use. Under popular pressure and following a court decision holding the exclusion of common characters unlawful, the list of "approved" characters was substantially extended. Furthermore, families whose names are not on these lists were permitted to continue using the older forms.

Historically, attempts to limit the number of kanji in use commenced in the mid-19th century, but did not become a matter of government intervention until after Japan's defeat in the Second World War. During the period of post-war occupation (and influenced by the views of some U.S. officials), various schemes including the complete abolition of kanji and exclusive use of rōmaji were considered. The kyōiku kanji scheme arose as a compromise solution.
Many major universities throughout the world provide Japanese language courses, and a number of secondary and even primary schools worldwide offer courses in the language. International interest in the Japanese language dates from the 1800s but has become more prevalent following Japan's economic bubble of the 1980s and the global popularity of Japanese pop culture since the 1990s. About 2.3 million people studied the language worldwide in 2003: 900,000 South Koreans, 389,000 Chinese, 381,000 Australians, and 140,000 Americans study Japanese in lower and higher educational institutions. In Japan, more than 90,000 foreign students study at Japanese universities and Japanese language schools, including 77,000 Chinese and 15,000 South Koreans in 2003. In addition, local governments and some NPO groups provide free Japanese language classes for foreign residents, including Japanese Brazilians and foreigners married to Japanese nationals.

The Japanese government provides standardized tests to measure spoken and written comprehension of Japanese for second language learners; the most prominent is the Japanese Language Proficiency Test (JLPT). The Japanese External Trade Organization JETRO organizes the Business Japanese Proficiency Test which tests the learner's ability to understand Japanese in a business setting. See also British Association for Japanese Studies.