- Language: Middle Japanese
- Alternate names: 中世日本語, chūsei nihongo
- Language code: xjpnm
- Language family: Japonic (SIL classification)
- Earlier form of: Japanese
- Number of speakers: Extinct
- Script: Hiragana, Katakana, and Han
Middle Japanese is a stage of the Japanese language following Late Old Japanese and proceeding Early Modern Japanese. It is a period of transition in which the language sheds many of its archaic features and becomes closer to its modern form.
The 9 verbal conjugations in Middle Japanese
|Upper Bigrade (上二段)||-i||-i||-u||-uru||-ure||-i(yo)|
|Lower Monograde (下一段)||-e||-e||-eru||-eru||-ere||-e(yo)|
|Lower Bigrade (下二段)||-e||-e||-u||-uru||-ure||-e(yo)|
Throughout the Middle Japanese period bigrade verbs gradually change into monogrades. This process comes to a completion during Early Modern Japanese.
This is in part a result of the merging of the conclusive (terminal) and attributive forms. The distinction is still existing in Okinawan.