Kanji (漢字; ) are the adopted logographic Chinese characters, known as hànzì, that are used in the Japanese writing system.
The earliest Japanese documents were probably written by bilingual Chinese or Korean officials employed at the Yamato period court. For example, the diplomatic correspondence from King Bu of Wa to Emperor Shun of Liu Song in 478 has been praised for its skillful use of allusion. Later, groups of people called fuhito were organized under the monarch to read and write Classical Chinese. During the reign of Empress Suiko (593–628), the Yamato court began sending full-scale diplomatic missions to China, which resulted in a large increase in Chinese literacy at the Japanese court.
The Japanese language had no written form at the time Chinese characters were introduced, and texts were written and read only in Chinese. Later, during the Heian period (794–1185), however, a system known as kanbun emerged, which involved using Chinese text with to allow Japanese speakers to restructure and read Chinese sentences, by changing word order and adding particles and verb endings, in accordance with the rules of Japanese grammar.
Chinese characters also came to be used to write Japanese words, resulting in the modern kana syllabaries. Around 650 CE, a writing system called man'yōgana (used in the ancient poetry anthology Man'yōshū) evolved that used a number of Chinese characters for their sound, rather than for their meaning. Man'yōgana written in Grass script evolved into hiragana, or hiragana, that is, "ladies' hand,"Hadamitzky, Wolfgang and Spahn, Mark (2012), Kanji and Kana: A Complete Guide to the Japanese Writing System, Third Edition, Rutland, VT: Tuttle Publishing. . p. 14. a writing system that was accessible to women (who were denied higher education). Major works of Heian-era literature by women were written in hiragana. Katakana emerged via a parallel path: monastery students simplified man'yōgana to a single constituent element. Thus the two other writing systems, hiragana and katakana, referred to collectively as kana, are descended from kanji.
In modern Japanese, kanji are used to write parts of the language (usually ) such as , adjective word stem, and verb word stem, while hiragana are used to write inflection verb and adjective endings and as phonetic complements to disambiguate readings ( okurigana), particles, and miscellaneous words which have no kanji or whose kanji is considered obscure or too difficult to read or remember. Katakana are mostly used for representing onomatopoeia, gairaigo (except those borrowed from Old Chinese), the names of plants and animals (with exceptions), and for emphasis on certain words.
These are simply guidelines, so many characters outside these standards are still widely known and commonly used; these are known as hyōgaiji.
Gaiji can be either user-defined characters or system-specific characters. Both are a problem for information interchange, as the codepoint used to represent an external character will not be consistent from one computer or operating system to another.
Gaiji were nominally prohibited in JIS X 0208-1997, and JIS X 0213-2000 used the range of code-points previously allocated to gaiji, making them completely unusable. Nevertheless, they persist today with NTT DoCoMo's "i-mode" service, where they are used for emoji (pictorial characters).
Approximately 2,000 to 3,000 characters are commonly used in Japan, a few thousand more find occasional use, and a total of 13,108 characters can be encoded in various Japanese Industrial Standards for kanji.
|a) semantic on||L1||L1|
|b) semantic kun||L1||L2|
|c) phonetic on||—||L1|
|d) phonetic kun||—||L2|
|*With L1 representing the language borrowed from (Chinese) and L2 representing the borrowing language (Japanese).Rogers, Henry (2005). Writing Systems: A Linguistic Approach. Oxford: Blackwell.|
Because of the way they have been adopted into Japanese, a single kanji may be used to write one or more different words – or, in some cases, morphemes – and thus the same character may be pronounced in different ways. From the point of view of the reader, kanji are said to have one or more different "readings". Although more than one reading may become activated in the brain, deciding which reading is appropriate depends on recognizing which word it represents, which can usually be determined from context, intended meaning, whether the character occurs as part of a compound word or an independent word, and sometimes location within the sentence. For example, 今日 is usually read kyō, meaning "today", but in formal writing is instead read konnichi, meaning "nowadays"; this is understood from context. Nevertheless, some cases are ambiguous and require a furigana gloss, which are also used simply for difficult readings or to specify a non-standard reading.
Kanji readings are categorized as either on'yomi (literally "sound reading", from Chinese) or kun'yomi (literally "meaning reading", native Japanese), and most characters have at least two readings, at least one of each. However, some characters have only a single reading, such as "chrysanthemum", an on-reading or "sardine", a kun-reading; kun-only are common for Japanese-coined kanji ( kokuji). Some common kanji have ten or more possible readings; the most complex common example is , which is read as sei, shō, nama, ki, o-u, i-kiru, i-kasu, i-keru, u-mu, u-mareru, ha-eru, and ha-yasu, totaling 8 basic readings (first 2 are on, rest are kun), or 12 if related verbs are counted as distinct; see for details.
Most often, a character will be used for both sound and meaning, and it is simply a matter of choosing the correct reading based on which word it represents. In other cases, a character is used only for sound ( ateji). In this case, pronunciation is still based on a standard reading, or used only for meaning (broadly a form of ateji, narrowly jukujikun). Therefore, only the full compound—not the individual character—has a reading. There are also special cases where the reading is completely different, often based on an historical or traditional reading.
The analogous phenomenon occurs to a much lesser degree in Chinese varieties, where there are literary and colloquial readings of Chinese characters – borrowed readings and native readings. In Chinese these borrowed readings and native readings are etymologically related, since they are between Chinese varieties (which are related), not from Chinese to Japanese (which are not related). They thus form doublets and are generally similar, analogous to different on'yomi, reflecting different stages of Chinese borrowings into Japanese.
Generally, on'yomi are classified into four types according to their region and time of origin:
|+ Examples (rare readings in parentheses)|
The most common form of readings is the kan-on one, and use of a non- kan-on reading in a word where the kan-on reading is well-known is a common cause of reading mistakes or difficulty, such as in detoxification, anti-poison ( go-on), where is usually instead read as kai. The go-on readings are especially common in Buddhist terminology such as paradise, as well as in some of the earliest loans, such as the Sino-Japanese numbers. The tō-on readings occur in some later words, such as chair, mattress, and a kind of paper lantern. The go-on, kan-on, and tō-on readings are generally cognate (with rare exceptions of homographs; see below), having a common origin in Old Chinese, and hence form linguistic doublets or triplets, but they can differ significantly from each other and from modern Chinese pronunciation.
In Chinese, most characters are associated with a single Chinese sound, though there are distinct literary and colloquial readings. However, some homographs (多音字 ) such as 行 ( háng or xíng) (Japanese: an, gō, gyō) have more than one reading in Chinese representing different meanings, which is reflected in the carryover to Japanese as well. Additionally, many Chinese syllables, especially those with an entering tone, did not fit the largely consonant-vowel (CV) phonotactics of classical Japanese. Thus most on'yomi are composed of two morae (beats), the second of which is either a lengthening of the vowel in the first mora (to ei, ō, or ū), the vowel i, or one of the syllables ku, ki, tsu, chi, fu (historically, later merged into ō), or moraic n, chosen for their approximation to the final consonants of Middle Chinese. It may be that palatalized consonants before vowels other than i developed in Japanese as a result of Chinese borrowings, as they are virtually unknown in words of native Japanese origin, but are common in Chinese.
On'yomi primarily occur in jukugo words, many of which are the result of the adoption, along with the kanji themselves, of Chinese words for concepts that either did not exist in Japanese or could not be articulated as elegantly using native words. This borrowing process is often compared to the English borrowings from Latin, Greek, and Norman French, since Chinese-borrowed terms are often more specialized, or considered to sound more erudite or formal, than their native counterparts (occupying a higher linguistic register). The major exception to this rule is family names, in which the native kun'yomi are usually used (though on'yomi are found in many personal names, especially men's names).
For instance, the character for east, , has the on'yomi tō, from Middle Chinese . However, Japanese already had two words for "east": higashi and azuma. Thus the kanji 東 had the latter readings added as kun'yomi. In contrast, the kanji 寸, denoting a Chinese unit of measurement (about 30 mm or 1.2 inch), has no native Japanese equivalent; it only has an on'yomi, sun, with no native kun'yomi. Most kokuji, Japanese-created Chinese characters, only have kun'yomi, although some have back-formed a pseudo- on'yomi by analogy with similar characters, such as dō, from dō, and there are even some, such as sen "gland", that have only an on'yomi.
Kun'yomi are characterized by the strict (C)V syllable structure of yamato kotoba. Most noun or adjective kun'yomi are two to three syllables long, while verb kun'yomi are usually between one and three syllables in length, not counting trailing hiragana called okurigana. Okurigana are not considered to be part of the internal reading of the character, although they are part of the reading of the word. A beginner in the language will rarely come across characters with long readings, but readings of three or even four syllables are not uncommon. This contrasts with on'yomi, which are monosyllabic, and is unusual in the Chinese family of scripts, which generally use one character per syllable – not only in Chinese, but also in Korean, Vietnamese, and Zhuang; polysyllabic Chinese characters are rare and considered non-standard.
''uketamawaru,'' ''kokorozashi,'' and ''mikotonori'' have five syllables represented by a single kanji, the longest readings in the ''jōyō'' character set. These unusually long readings are due to a single character representing a compound word:
Longer readings exist for non-Jōyō characters and non-kanji symbols, where a long gairaigo word may be the reading (this is classed as kun'yomi – see single character gairaigo, below) – the character has the seven kana reading センチメートル senchimētoru "centimeter", though it is generally written as "cm" (with two half-width characters, so occupying one space); another common example is '%' (the percent sign), which has the five kana reading パーセント pāsento. Further, some Jōyō characters have long non-Jōyō readings (students learn the character, but not the reading), such as omonpakaru for 慮る.
In a number of cases, multiple kanji were assigned to cover a single Japanese word. Typically when this occurs, the different kanji refer to specific shades of meaning. For instance, the word なおす, naosu, when written 治す, means "to heal an illness or sickness". When written 直す it means "to fix or correct something". Sometimes the distinction is very clear, although not always. Differences of opinion among reference works is not uncommon; one dictionary may say the kanji are equivalent, while another dictionary may draw distinctions of use. As a result, native speakers of the language may have trouble knowing which kanji to use and resort to personal preference or by writing the word in hiragana. This latter strategy is frequently employed with more complex cases such as もと moto, which has at least five different kanji: 元, 基, 本, 下, and 素, the first three of which have only very subtle differences. Another notable example is sakazuki "sake cup", which may be spelt as at least five different kanji: 杯, 盃, 巵/卮, and 坏; of these, the first two are common – formally 杯 is a small cup and 盃 a large cup.
Local dialectical readings of kanji are also classified under kun'yomi, most notably readings for words in Ryukyuan languages. Further, in rare cases gairaigo (borrowed words) have a single character associated with them, in which case this reading is formally classified as a kun'yomi, because the character is being used for meaning, not sound. This is discussed under single character gairaigo, below.
Formally, these are referred to as jūbako reading and yutō reading. Note that in both these words, the on'yomi has a long vowel; long vowels in Japanese generally come from Chinese, hence distinctive of on'yomi. These are the Japanese form of . Other examples include "place", kun-on, "golden", on-kun and the martial art Aikido", kun-on-on.
Ateji often use mixed readings. For instance the city of Sapporo, whose name derives from the Ainu language and has no meaning in Japanese, is written with the on-kun compound 札幌 (which includes sokuon as if it were a purely on compound).
and are readings of kanji combinations that have no direct correspondence to the characters' individual ''on'yomi'' or ''kun'yomi,''. From the point of view of the character, rather than the word, this is known as a difficult reading, and these are listed in kanji dictionaries under the entry for the character.
Gikun are when non-standard kanji are used, generally for effect, such as using with reading fuyu ("winter"), rather than the standard character .
Jukujikun are when the standard kanji for a word are related to the meaning, but not the sound. The word is pronounced as a whole, not corresponding to sounds of individual kanji. For example, ("this morning") is jukujikun, and read neither as *ima'asa, the kun'yomi of the characters, nor konchō, the on'yomi of the characters, nor any combination thereof. Instead it is read as kesa, a native bisyllabic Japanese word that may be seen as a single morpheme, or as a fusion of kyō (previously kefu), "today", and asa, "morning". Likewise, ("tomorrow") is jukujikun, and read neither as akari(no)hi, the kun'yomi of the characters, nor meinichi, the on'yomi of the characters, nor any combination thereof. Instead it is read as ashita, a native multisyllabic Japanese word that may be seen as a single morpheme.
Jukujikun are primarily used for some native Japanese words, such as Yamato ( or , the name of a Japanese province as well as ancient name for Japan), and for some old borrowings, such as willow leaf fish from Ainu, smoke grass from Portuguese, or bīru (, wheat alcohol) from Dutch, especially if the word was borrowed before the Meiji period. Words whose kanji are jukujikun are often usually written as hiragana (if native), or katakana (if borrowed); some old borrowed words are also written as hiragana, especially Portuguese loanwords such as karuta (かるた) from Portuguese "carta" (Eng: card), tempura (てんぷら) from Portuguese "tempora" (Eng: time), and pan (ぱん) from Spanish "pan" (Eng: bread), as well as tabako (たばこ).
Jukujikun are quite varied. Often the kanji compound for jukujikun is idiosyncratic and created for the word, with the corresponding Chinese word not existing; in other cases a kanji compound for an existing Chinese word is reused, where the Chinese word and on'yomi may or may not be used in Japanese; for example, reindeer is jukujikun for tonakai, from Ainu, but the on'yomi reading of junroku is also used. In some cases Japanese coinages have subsequently been borrowed back into Chinese, such as monkfish.
The underlying word for jukujikun is a native Japanese word or foreign borrowing, which either does not have an existing kanji spelling (either kun'yomi or ateji) or for which a new kanji spelling is produced. Most often the word is a noun, which may be a simple noun (not a compound or derived from a verb), or may be a verb form or a fusional pronunciation; for example sumo is originally from the verb to vie, while today is fusional. In rare cases jukujikun is also applied to inflectional words (verbs and adjectives), in which case there is frequently a corresponding Chinese word.
Examples of jukujikun for inflectional words follow. The most common example of a jukujikun adjective is cute, originally kawayu-i; the word 可愛 is used in Chinese, but the corresponding on'yomi is not used in Japanese. By contrast, "appropriate" can be either in jukujikun or in on'yomi are both used; the -shii ending is because these were formerly a different class of adjectives. A common example of a verb with jukujikun is to spread, to be in vogue, corresponding to on'yomi ryūkō. A sample jukujikun deverbal (noun derived from a verb form) is extortion, from to extort, spelling from extortion. See 義訓 and 熟字訓 for many more examples. Note that there are also compound verbs and, less commonly, compound adjectives, and while these may have multiple kanji without intervening characters, they are read using usual kun'yomi; examples include face-whitening and sly.
Typographically, the furigana for jukujikun are often written so they are centered across the entire word, or for inflectional words over the entire root – corresponding to the reading being related to the entire word – rather than each part of the word being centered over its corresponding character, as is often done for the usual phono-semantic readings.
Broadly speaking, jukujikun can be considered a form of ateji, though in narrow usage "ateji" refers specifically to using characters for sound and not meaning (sound-spelling), rather than meaning and not sound (meaning-spelling), as in jukujikun.
Many jukujikun (established meaning-spellings) began life as gikun (improvised meaning-spellings). Occasionally a single word will have many such kanji spellings; an extreme example is Lesser Cuckoo]], which may be spelt in a great many ways, including , , , , , , , ,, , and – many of these variant spellings are particular to haiku poems.
For example, there is the surname 小鳥遊 (literally, "little birds at play") that implies there are no predators, such as hawks, present. Pronounced, " kotori asobu". The name then can also mean 鷹がいない ( taka ga inai, literally, "no hawks around") and it can be shortened to be pronounced as Takanashi.
Homographs exist, however, which can sometimes be deduced from context, and sometimes cannot, requiring a glossary. For example, may be read either as kyō "today (informal)" (special fused reading for native word) or as konnichi "these days (formal)" ( on'yomi); in formal writing this will generally be read as konnichi. In some cases multiple readings are common, as in "pork soup", which is commonly pronounced both as ton-jiru (mixed on-kun) and buta-jiru ( kun-kun), with ton somewhat more common nationally. Inconsistencies abound – for example gyū-niku "beef" and yō-niku "mutton" have on-on readings, but buta-niku "pork" and tori-niku "poultry" have kun-on readings.
The main guideline is that a single kanji followed by okurigana (hiragana characters that are part of the word) – as used in native verbs and adjectives – always indicates kun'yomi, while kanji compounds (kango) usually use on'yomi, which is usually kan-on; however, other on'yomi are also common, and kun'yomi are also commonly used in kango. For a kanji in isolation without okurigana, it is typically read using their kun'yomi, though there are numerous exceptions. For example, "iron" is usually read with the on'yomi tetsu rather than the kun'yomi kurogane. Chinese on'yomi which are not the common kan-on reading are a frequent cause of difficulty or mistakes when encountering unfamiliar words or for inexperienced readers, though skilled natives will recognize the word; a good example is detoxification, anti-poison ( go-on), where 解 is usually instead read as kai.
Okurigana are used with kun'yomi to mark the inflected ending of a native verb or adjective, or by convention. Note that Japanese verbs and adjectives are closed class, and do not generally admit new words (borrowed Chinese vocabulary, which are nouns, can form verbs by adding to do at the end, and adjectives via -no or -na, but cannot become native Japanese vocabulary, which inflect). For example: aka-i "red", atara-shii "new", mi-ru "(to) see". Okurigana can be used to indicate which kun'yomi to use, as in ta-beru versus ku-u (casual), both meaning "(to) eat", but this is not always sufficient, as in , which may be read as a-ku or hira-ku, both meaning "(to) open". is a particularly complicated example, with multiple kun and on'yomi – see for details. Okurigana is also used for some nouns and adverbs, as in nasake "sympathy", kanarazu "invariably", but not for kane "money", for instance. Okurigana is an important aspect of kanji usage in Japanese; see that article for more information on kun'yomi orthography
Kanji occurring in jukugo are generally read using on'yomi, especially for four-character compounds ( yojijukugo). Though again, exceptions abound, for example, jōhō "information", gakkō "school", and shinkansen "bullet train" all follow this pattern. This isolated kanji versus compound distinction gives words for similar concepts completely different pronunciations. "north" and "east" use the kun'yomi kita and higashi, being stand-alone characters, but "northeast", as a compound, uses the on'yomi hokutō. This is further complicated by the fact that many kanji have more than one on'yomi: is read as sei in sensei "teacher" but as shō in isshō "one's whole life". Meaning can also be an important indicator of reading; is read i when it means "simple", but as eki when it means "divination", both being on'yomi for this character.
These rules of thumb have many exceptions. Kun'yomi compound words are not as numerous as those with on'yomi, but neither are they rare. Examples include tegami "letter", higasa "parasol", and the famous kamikaze "divine wind". Such compounds may also have okurigana, such as (also written ) karaage "Chinese-style fried chicken" and origami, although many of these can also be written with the okurigana omitted (for example, or ).
Similarly, some on'yomi characters can also be used as words in isolation: ai "love", Zen, ten "mark, dot". Most of these cases involve kanji that have no kun'yomi, so there can be no confusion, although exceptions do occur. Alone may be read as kin "gold" or as kane "money, metal"; only context can determine the writer's intended reading and meaning.
Multiple readings have given rise to a number of , in some cases having different meanings depending on how they are read. One example is , which can be read in three different ways: jōzu (skilled), uwate (upper part), or kamite (stage left/house right). In addition, has the reading umai (skilled). More subtly, has three different readings, all meaning "tomorrow": ashita (casual), asu (polite), and myōnichi (formal). Furigana (reading glosses) is often used to clarify any potential ambiguities.
Conversely, in some cases homophonous terms may be distinguished in writing by different characters, but not so distinguished in speech, and hence potentially confusing. In some cases when it is important to distinguish these in speech, the reading of a relevant character may be changed. For example, (privately established, esp. school) and (city established) are both normally pronounced shi-ritsu; in speech these may be distinguished by the alternative pronunciations watakushi-ritsu and ichi-ritsu. More informally, in legal jargon "preamble" and "full text" are both pronounced zen-bun, so may be pronounced mae-bun for clarity, as in "Have you memorized the preamble not of the constitution?". As in these examples, this is primarily using a kun'yomi for one character in a normally on'yomi term.
As stated above, jūbako and yutō readings are also not uncommon. Indeed, all four combinations of reading are possible: on-on, kun-kun, kun-on and on-kun.
Several famous place names, including those of Japan itself ( Nihon or sometimes Nippon), those of some cities such as Tokyo ( Tōkyō) and Kyoto ( Kyōto), and those of the main islands Honshu ( Honshū), Kyushu ( Kyūshū), Shikoku ( Shikoku), and Hokkaido ( Hokkaidō) are read with on'yomi; however, the majority of Japanese place names are read with kun'yomi: Ōsaka, Aomori, Hakone. Names often use characters and readings that are not in common use outside of names. When characters are used as abbreviations of place names, their reading may not match that in the original. The Osaka () and Kobe () baseball team, the Hanshin Tigers () Tigers, take their name from the on'yomi of the second kanji of Ōsaka and the first of Kōbe. The name of the Keisei () railway line – linking Tokyo () and Narita () – is formed similarly, although the reading of from is kei, despite kyō already being an on'yomi in the word Tōkyō.
Japanese family names are also usually read with kun'yomi: Yamada, Tanaka, Suzuki. Japanese Given name often have very irregular readings. Although they are not typically considered jūbako or yutō, they often contain mixtures of kun'yomi, on'yomi and nanori, such as Daisuke on-kun, Natsumi kun-on. Being chosen at the discretion of the parents, the readings of given names do not follow any set rules, and it is impossible to know with certainty how to read a person's name without independent verification. Parents can be quite creative, and rumours abound of children called Āsu ("Earth") and Enjeru ("Angel"); neither are common names, and have normal readings chikyū and tenshi respectively. Some common Japanese names can be written in multiple ways, e.g. Akira can be written as , , , , , , , , , , , , , , , , and many other characters and kanji combinations not listed, Satoshi can be written as , , , , , , , , , , , , , , , , , , etc., and Haruka can be written as , , , , , , , , and several other possibilities. Common patterns do exist, however, allowing experienced readers to make a good guess for most names. To alleviate any confusion on how to pronounce the names of other Japanese people, most official Japanese documents require Japanese to write their names in both kana and kanji.
Chinese place names and Chinese personal names appearing in Japanese texts, if spelled in kanji, are almost invariably read with on'yomi. Especially for older and well-known names, the resulting Japanese pronunciation may differ widely from that used by modern Chinese speakers. For example, Mao Zedong's name is pronounced as Mō Takutō in Japanese, and the name of the legendary Monkey King, Sun Wukong, is pronounced Son Gokū () in Japanese.
Today, Chinese names that are not well known in Japan are often spelled in katakana instead, in a form much more closely approximating the native Chinese pronunciation. Alternatively, they may be written in kanji with katakana furigana. Many such cities have names that come from non-Chinese languages like Mongolian or Manchu. Examples of such not-well-known Chinese names include:
|Hong Kong||Xianggang||Hēung Góng||ホンコン||Honkon|
|Beijing (formerly Peking)||Beijing||Bāk Gīng||ペキン||Pekin|
|Nanjing (formerly Nanking)||Nanjing||Nàahm Gīng||ナンキン||Nankin|
|Kaohsiung||Gaoxiong / Dagou||Gōu Hùhng||/||カオシュン / タカオ||Kaoshun / Takao|
In some cases the same kanji can appear in a given word with different readings. Normally this occurs when a character is duplicated and the reading of the second character has voicing ( rendaku), as in 人人 hito-bito "people" (more often written with the iteration mark as ), but in rare cases the readings can be unrelated, as in "hop around", more often written 飛び跳ねる.
Likewise, the process of character simplification in mainland China since the 1950s has resulted in the fact that Japanese speakers who have not studied Chinese may not recognize some simplified characters.
Since kokuji are generally devised for existing native words, these usually only have native kun readings. However, they occasionally have a Chinese on reading, derived from a phonetic, as in , dō,, and in rare cases only have an on reading, as in , sen, from 泉, which was derived for use in technical compounds (腺 means "gland", hence used in medical terminology).
The majority of kokuji are ideogrammatic compounds (会意字), meaning that they are composed of two (or more) characters, with the meaning associated with the combination. For example, is composed of (person radical) plus (action), hence "action of a person, work". This is in contrast to kanji generally, which are overwhelmingly phono-semantic compounds. This difference is because kokuji were coined to express Japanese words, so borrowing existing (Chinese) readings could not express these – combining existing characters to logically express the meaning was the simplest way to achieve this. Other illustrative examples (below) include 榊 sakaki tree, formed as "tree" and 神 "god", literally "divine tree", and 辻 tsuji "crossroads, street" formed as 辶 () "road" and 十 "cross", hence "cross-road".
In terms of meanings, these are especially for natural phenomena (esp. flora and fauna species) that were not present in ancient China, including a very large number of fish, such as (sardine), (codfish), (seaperch), and (sillago), and trees, such as (evergreen oak), (Japanese cedar), (birch, maple) and (spindle tree). In other cases they refer to specifically Japanese abstract concepts, everyday words (like ), or later technical coinages (such as ).
There are hundreds of kokuji in existence.. Many are rarely used, but a number have become commonly used components of the written Japanese language. These include the following:
Jōyō kanji has about 9 kokuji; there is some dispute over classification, but generally includes these:
Some of these characters (for example, , "gland")Buck, James H. (October 15, 1969) "Some Observations on kokuji" in The Journal-Newsletter of the Association of Teachers of Japanese, Vol. 6, No. 2, pp. 45–9. have been introduced to China. In some cases the Chinese reading is the inferred Chinese reading, interpreting the character as a phono-semantic compound (as in how on readings are sometimes assigned to these characters in Chinese), while in other cases (such as ), the Japanese on reading is borrowed (in general this differs from the modern Chinese pronunciation of this phonetic). Similar coinages occurred to a more limited extent in Korea and Vietnam.
Historically, some kokuji date back to very early Japanese writing, being found in the Man'yōshū, for example – iwashi "sardine" dates to the Nara period (8th century) – while they have continued to be created as late as the late 19th century, when a number of characters were coined in the Meiji era for new scientific concepts. For example, some characters were produced as regular compounds for some (but not all) SI units, such as ( "meter" + "thousand, kilo-") for kilometer, ( "liter" + "thousand, kilo-") for kiloliter, and ( "gram" + "thousand, kilo-") for kilogram – see Chinese characters for SI units for details. However, SI units in Japanese today are almost exclusively written using rōmaji or katakana such as or for km, for kl, and or for kg.
In Japan the kokuji category is strictly defined as characters whose earliest appearance is in Japan. If a character appears earlier in the Chinese literature, it is not considered a kokuji even if the character was independently coined in Japan and unrelated to the Chinese character (meaning "not borrowed from Chinese"). In other words, kokuji are not simply characters that were made in Japan, but characters that were first made in Japan. An illustrative example is monkfish. This spelling was created in Edo period Japan from the ateji (phonetic kanji spelling) for the existing word ankō by adding the radical to each character – the characters were "made in Japan". However, is not considered kokuji, as it is found in ancient Chinese texts as a corruption of 鰋 (魚匽). is considered kokuji, as it has not been found in any earlier Chinese text. Casual listings may be more inclusive, including characters such as . at demonstrates this, listing both and as kokuji, but starring and stating that dictionaries do not consider it to be a kokuji. Another example is , which is sometimes not considered kokuji due to its earlier presence as a corruption of Chinese 榨.
|rattan, cane, vinethe word for wisteria being "紫藤", with the addition of "紫", "purple"|
|rinse, minor river (Cantonese)|
|catfish (rare, usually written 鯰)|
Another abbreviated symbol is , in appearance a small katakana "ke", but actually a simplified version of the kanji , a general counter. It is pronounced "ka" when used to indicate quantity (such as 六ヶ月, rok kagetsu "six months") or "ga" in place names like 霞ヶ関.
The way how these symbols may be produced on a computer depends on the operating system. In OS X, typingwill reveal the symbol as well as , and . To produce , type . Under Windows, typingwill reveal some of these symbols, while in Google IME,may be used.
Other kanji sorting methods, such as the SKIP system, have been devised by various authors.
Modern general-purpose Japanese dictionaries (as opposed to specifically character dictionaries) generally collate all entries, including words written using kanji, according to their kana representations (reflecting the way they are pronounced). The gojūon ordering of kana is normally used for this purpose.
Students studying Japanese as a foreign language are often required by a curriculum to acquire kanji without having first learned the vocabulary associated with them. Strategies for these learners vary from copying-based methods to mnemonic-based methods such as those used in James Heisig's series Remembering the Kanji. Other textbooks use methods based on the etymology of the characters, such as Mathias and Habein's The Complete Guide to Everyday Kanji and Henshall's A Guide to Remembering Japanese Characters. Pictorial mnemonics, as in the text Kanji Pict-o-graphix, are also seen.
The Japanese government provides the Kanji kentei ( Nihon kanji nōryoku kentei shiken; "Test of Japanese Kanji Aptitude"), which tests the ability to read and write kanji. The highest level of the Kanji kentei tests about six thousand kanji.