grammaticality - Is "who did what" grammatically correct?

Sometimes I wish to know what each person in a group of people did, or where each person went, or which book goes where. Is it correct to say,

• Who went where?


• Who did what?


• Who told whom?



• Which book goes where?

If not, what is the grammatical way of framing such questions?

Answer

All four are grammatically correct.

The comments are good here, but I wish people would put answers in the answers section because the question remains unanswered even though the OP has the answer(s) in the comments!