Which thing or which particular one of many: What are you having for dinner? What did she say?

Which kind, character, or designation: What are these objects?

One of how much value or significance: What are possessions to a dying man?

That which; the thing that: Listen to what I tell you.

Whatever thing that: come what may.

Informal. Something: I’ll tell you what.

Nonstandard. Which, who, or that: It’s the poor what gets the blame.

Or it can be used as a adjetive:

Which one or ones of several or many: What college are you attending? You should know what musical that song is from.

Whatever: They soon repaired what damage had been done.

How great; how astonishing: What a fool!

or it can be used as an adverb:

How much; in what respect; how: What does it matter?

I hope this helps!