Yotsugana
Yotsugana (四つ仮名, literally "four kana") are a set of four specific kana, じ, ぢ, ず, づ (in the Nihon-shiki romanization system: zi, di, zu, du), used in the Japanese writing system.
They historically represented four distinct voiced morae (syllables) in the Japanese language.
However, most dialects, such as Standard Japanese-speakers, have undergone mergers and now pronounce two sounds.
Shortly after World War II ended, the discrepancy between kana orthography and pronunciation was rectified as part of a general orthographic reform, the Gendai Kanazukai, or modern kana orthography.
The following table shows some of the differentiations among yotsugana characters expressed in regional dialects across Japan:
1 sound (
zi
=
di
=
zu
=
du
)
2 sounds (
zi
=
di
≠
zu
=
du
)
3 sounds (
zi
=
di
≠
zu
≠
du
)
4 sounds (
zi
≠
di
≠
zu
≠
du
)