In the Japanese language, the gojūon (五十音, Japanese pronunciation: [ɡo(d)ʑɯꜜːoɴ], lit. "fifty sounds") is a traditional system ordering kana by their component phonemes, roughly analogous to alphabetical order. The "fifty" (gojū) in its name refers to the 5×10 grid in which the characters are displayed. Each kana, which may be a hiragana or katakana character, corresponds to one sound in Japanese. As depicted at the right using hiragana characters, the sequence begins with あ (a), い (i), う (u), え (e), お (o), then continues with か (ka), き (ki), く (ku), け (ke), こ (ko), and so on and so forth for a total of ten rows of five columns.
Although nominally containing 50 characters, the grid is not completely filled, and, further, there is an extra character added outside the grid at the end: with 5 gaps and 1 extra character, the current number of distinct kana in a syllabic chart in modern Japanese is therefore 46. Some of these gaps have always existed as gaps in sound: there was no yi or wu in Old Japanese, and ye disappeared in Early Middle Japanese, predating the kana; the kana for i, u and e double up for those phantom values. Also, with the spelling reforms after World War II, the kana for wi and we were replaced with i and e, the sounds they had developed into. The kana for syllabic n (hiragana ん) is not part of the grid, as it was introduced long after gojūon ordering was devised. (Previously mu (hiragana む) was used for this sound.)
The gojūon contains all the basic kana, but it does not include:
The gojūon order is the prevalent system for collating Japanese in Japan. For example, dictionaries are ordered using this method. Other systems used are the iroha ordering, and, for kanji, the radical ordering.
The monk Kūkai introduced the Siddhaṃ script to Japan in 806 on his return from China. Belonging to the Brahmic script, the Sanskrit ordering of letters was used for it. Buddhist monks who invented katakana chose to use the word order of Sanskrit and Siddham, since important Buddhist writings were written with those alphabets.
In an unusual set of events, although it uses Sanskrit organization (grid, with order of consonants and vowels), it also uses the Chinese order of writing (in columns, right-to-left).
The order of consonants and vowels, and the grid layout, originates in Sanskrit shiksha (śikṣā, Hindu phonetics and phonology), and Brāhmī script, as reflected throughout the Brahmic family of scripts.
The Sanskrit was written left-to-right, with vowels changing in rows, not columns; writing the grid vertically follows Chinese writing convention.
There are three ways in which the grid does not exactly accord with Sanskrit ordering of Modern Japanese; that is because the grid is based on Old Japanese, and some sounds have changed in the interim.
What is now s/さ was previously pronounced [ts], hence its location corresponding to Sanskrit /t͡ʃ/; in Sanskrit /s/ appears towards the end of the list.
Kana starting with h (e.g. は), b (e.g. ば) and p (e.g. ぱ) are placed where p/b are in Sanskrit (in Sanskrit, h is at the end) and the diacritics do not follow the usual pattern: p/b (as in Sanskrit) is the usual unvoiced/voiced pattern, and [h] has different articulation. This is because /h/ was previously [p], and pronouncing /h/ as [h] is recent.
(More detail at Old Japanese: Consonants; in brief: prior to Old Japanese, modern /h/ was presumably [p], as in Ryukyuan languages. Proto-Japanese is believed to have split into Old Japanese and the Ryukyuan languages in the Yamato period (250–710). In Old Japanese (from 9th century) and on to the 17th century, /h/ was pronounced [ɸ]. The earliest evidence was from 842, by the monk Ennin, writing in the Zaitōki that Sanskrit /p/ is more labial than Japanese. The Portuguese later transcribed the は-row as fa/fi/fu/fe/fo.)
Syllable-final n (ん) was not present in Old Japanese (it developed following Chinese borrowings), does not fit with other characters due to having no vowel, and thus is attached at the end of the grid, as in Sanskrit treatment of miscellaneous characters.
The earliest example of a gojūon-style layout dates from a manuscript known as Kujakukyō Ongi (孔雀経音義) dated c. 1004–1028. In contrast, the earliest example of the alternative iroha ordering is from the 1079 text Konkōmyō Saishōōkyō Ongi (金光明最勝王経音義).
Today the gojūon system forms the basis of input methods for Japanese mobile phones – each key corresponds to a column in the gojūon, while the number of presses determines the row. For example, the '2' button corresponds to the ka-column (ka, ki, ku, ke, ko), and the button is pressed repeatedly to get the intended kana.
This table uses the vertical system of Japanese writing, and should be read from the top down, starting from the rightmost column, then to the left. In each entry, the top entry is the hiragana, the second entry is the corresponding katakana, the third entry is the Hepburn romanization of the kana, and the fourth entry is the pronunciation written in the International Phonetic Alphabet (IPA). Please see Japanese phonology for more details on the individual sounds.
The rows are referred to as dan (段), and the columns as gyō (行). They are named for their first entry, thus the rows are あ段 い段 う段 え段 お段 while the columns are (in left-to-right order) わ行 ら行 や行 ま行 は行 な行 た行 さ行 か行 あ行. These are sometimes written in katakana, such as ア行, and conspicuously used when referring to Japanese verb conjugation – for example, the verb yomu (読む, "read") is of ma-gyō go-dan katsuyō (マ行五段活用, "ma-column 5-class conjugation") type.
In the ordering based on the gojūon, smaller versions of kana are treated in the same way as full-size versions:
Voiced versions (those with a dakuten) are classified under their unvoiced versions; If the words are otherwise identical, the voiced version is placed after the unvoiced; handakuten are placed after dakuten. For example,
In order to remember the gojūon, various mnemonics have been devised. For example,
The first letters in these phrases give the ordering of the non-voiced initial sounds.
For vowel ordering, the vowel sounds in the following English phrase may be used as a mnemonic:
The vowel sounds in the English words approximate the Japanese vowels: a, i, u, e, o.
One can also use
to remember the order of the vowels.