Yōon

Yōon or Youon (拗音?, contracted word or diphthong) is a feature of the Japanese language in which a mora is formed with an added [j] sound.

Yōon are represented in hiragana using a kana ending in i, such as き (ki), plus a smaller-than-usual version of one of the three y kana, ya, yu or yo. For example kyō, "today", is written きょう, using a small version of the yo kana, よ. Contrast this with kiyō, "skillful", which is written きよう, with a full-sized yo kana. In the past, in historical kana usage, yōon were not distinguished with the smaller kana, and had to be guessed by context.

In earlier Japanese, yōon could also be formed with the kana wa, wi, we, and wo; for example, くゎ/クヮ kwa, く/ク kwi, く/ク kwe, く/ク kwo. Although obsolete in modern Japanese, kwa and kwi can still be found in several of the Ryukyuan languages today, while kwe is formed with the digraph くぇ. Instead of the kana き, these are formed with the kana for ku, く/ク.

Table

Yōon (拗音)
katakana
ya yu yo
ki キャ kya キュ kyu キョ kyo
shi シャ sha シュ shu ショ sho
chi チャ cha チュ chu チョ cho
ni ニャ nya ニュ nyu ニョ nyo
hi ヒャ hya ヒュ hyu ヒョ hyo
mi ミャ mya ミュ myu ミョ myo
ri リャ rya リュ ryu リョ ryo
dakuten
gi ギャ gya ギュ gyu ギョ gyo
ji ジャ ja ジュ ju ジョ jo
bi ビャ bya ビュ byu ビョ byo
handakuten
pi ピャ pya ピュ pyu ピョ pyo
hiragana
ya yu yo
ki きゃ kya きゅ kyu きょ kyo
shi しゃ sha しゅ shu しょ sho
chi ちゃ cha ちゅ chu ちょ cho
ni にゃ nya にゅ nyu にょ nyo
hi ひゃ hya ひゅ hyu ひょ hyo
mi みゃ mya みゅ myu みょ myo
ri りゃ rya りゅ ryu りょ ryo
dakuten
gi ぎゃ gya ぎゅ gyu ぎょ gyo
ji じゃ ja じゅ ju じょ jo
bi びゃ bya びゅ byu びょ byo
handakuten
pi ぴゃ pya ぴゅ pyu ぴょ pyo