Japanese question... -azu or -zu ending... same as -nai?

Question

When I see an -azu ending (for 5 dan verbs) or -zu (for 1 dan) I get the impression from the context that it is its negative form.

Is hanasazu same as hanasanai, for example? tabezu-tabenai?

Answer 1

Using -zu ni makes it a "without" kind of negative.

Kare wa yuushoku o tabezu ni nemashita.

彼は夕食を食べずに寝ました。

He went to bed without eating dinner.

It's negative to an extent. The fact someone did something without doing something else prior.

Tasukezu ni, hashi wo tsukaimasu.

助けずに、箸を使います。

I use chopsticks without help.