Use of who and whom

I get confused regarding the use of who and whom. When are you supposed to use each. Also, which is correct: It depends on whom or who you ask?

I was going to explain this myself but grammar girl provides a great explination. Check it out here: whom vs who

If you don't have time...remember her quick tip.

Can you answer the question with him or he?

If you can answer the question with him...it ends with m and therefore you need to use whom. If you can answer the question with he then just use who. High five grammar girl!