Japanese - Grammar Reference
「じゃない」Declare something is not
「じゃない」Declare something is not
Is not, are not
じゃない is a commonly used way to say that something is not something. Or put differently, it is used to express is not A or are not A. It is the negative counterpart of だ.
To negate a noun, simply attach じゃない to it.
先生じゃない。
Isn't/am not a teacher.
Aren't teachers.
猫じゃない。
Isn't/am not a cat.
Aren't cats.
Formation
な-Adjective + じゃない
きれいじゃない
Noun + じゃない
学生じゃない