何不【hébù】

何不 means "why not" and turns a question into a suggestion. 何 is the written "what, why", so 何不 is the formal counterpart of spoken 为什么不 or 干吗不. It goes after the subject and before the verb.

The question expects no answer. It gives a reason, often with 既然 "since", and then proposes the obvious step.

Looking back: a mild reproach

About something already past, 何不 says the person should have done it. 呢 at the end softens it.

何不 or 何必

何必 is the opposite: "why bother", saying something is unnecessary. 何不去 urges you to go; 何必去 says there's no need.

Where the subject goes

何不 is an adverb, so the subject stands before it, the same as with 也 or 都.

• × 何不你问问他 → 你何不问问他