Verbs · N5–N4
The ない-form: plain negative verbs
The negative base used in casual speech and many larger patterns.
In short
ない attaches through each verb group’s negative conjugation: 食べる→食べない, 書く→書かない, する→しない, 来る→来ない.
How it works
It can stand as a plain negative predicate or feed constructions such as ないで, なくてもいい, なければならない and ないほうがいい.
Useful contrast
The polite negative ません and plain negative ない differ mainly in register and grammatical environment.
Examples
今日は行かない。
I am not going today.
食べないでください。
Please do not eat it.
Common pitfall
For godan verbs, watch う→わ: 買う becomes 買わない, not *買あない.