How does Japanese grammar think about verb negation?


In a recent comment I claimed that ない was a verb which was the negative form
of ある. I was surprised by the reply that "ない is an adjective (or adjective-
like auxiliary) anyway, not a form of ある".

Obviously I know that ない **behaves like** an adjective, but my confusion lies
in how Japanese people think about verb negation. Is ある->ない just a special
case? For example, does Japanese grammar think of 食べない as a verb which is the
negation of 食べる, or does it think of it as an adjective? Maybe I'm just trying
to apply western principles to Japanese grammar and my question doesn't even
make sense. I'm not sure.




That is confusing ない as
[adjective](https://dictionary.goo.ne.jp/word/%E3%81%AA%E3%81%84/#jn-162263)
and ない as [auxiliary
verb](https://dictionary.goo.ne.jp/word/%E3%81%AA%E3%81%84/#jn-162271).

The standalone ない is an adjective, but ない in 食べない is an auxiliary verb. This
is basically similar to negations in other languages in the sense that
negation is expressed by a functional word that is not used by itself. (Or
maybe Japanese grammarians stipulated so that it looks that way.)




That is confusing ない as
[adjective](https://dictionary.goo.ne.jp/word/%E3%81%AA%E3%81%84/#jn-162263)
and ない as [auxiliary
verb](https://dictionary.goo.ne.jp/word/%E3%81%AA%E3%81%84/#jn-162271).

The standalone ない is an adjective, but ない in 食べない is an auxiliary verb. This
is basically similar to negations in other languages in the sense that
negation is expressed by a functional word that is not used by itself. (Or
maybe Japanese grammarians stipulated so that it looks that way.)

