"Who" and "Whom"

If you could use the word "He", use "Who". If you could use the word "Him", use "Whom".

WHO:
He is there. Who is there?

He did it. Who did it?

Notice that "Who" is followed by a verb. Who is, who does, etc.

WHOM:
I gave it to him. You gave it to whom?

I love him. Whom do you love?

Notice that the verb is either before "whom", or else there are other words in the way. The person referred to as "whom" is not doing anything.

Suppose one person punches another person. The person doing something (punching) is "who". The person getting punched is "whom". You might ask, "Who hit whom?"