Haiku - Syllables or on in Haiku

Syllables or on in Haiku

In contrast to English verse typically characterized by meter, Japanese verse counts sound units known as "on" or morae. Traditional haiku consist of 17 on, in three phrases of five, seven and five on respectively. Among contemporary poems teikei (定型 fixed form) haiku continue to use the 5-7-5 pattern while jiyuritsu (自由律 free form) haiku do not. One of the examples below illustrates that traditional haiku masters were not always constrained by the 5-7-5 pattern.

Although the word "on" is sometimes translated as "syllable", one on is counted for a short syllable, two for an elongated vowel, diphthong, or doubled consonant, and one for an "n" at the end of a syllable. Thus, the word "haibun", though counted as two syllables in English, is counted as four on in Japanese (ha-i-bu-n); and the word "on" itself, which English-speakers would view as a single syllable, comprises two on: the short vowel o and the moraic nasal n̩. This is illustrated by the Issa haiku below, which contains 17 on but only 15 syllables. Conversely, some sounds, such as "kyo" (きょ) can be perceived as two syllables in English but are a single on in Japanese.

The word onji (音字; "sound symbol") is sometimes used in referring to Japanese sound units in English although this word is no longer current in Japanese. In Japanese, each on corresponds to a kana character (or sometimes digraph) and hence ji (or "character") is also sometimes used as the count unit.

In 1973, the Haiku Society of America noted that the norm for writers of haiku in English was to use 17 syllables, but they also noted a trend toward shorter haiku.

Some translators of Japanese poetry have noted that about 12 syllables in English approximate the duration of 17 Japanese on.