wait, did i just learn something?

ok. yes. i took AP english junior & senior year of HS, but i can never remember when to use "who" or "whom"

here is a quick lesson:

You might say: Who

You might mean: Whom

Why: It all depends. Do you need a subject or an object?

A subject (who) is the actor of the sentence: "Who left the roller skates on the sidewalk?"

An object (whom) is the acted-upon: "Whom are you calling?"

so, i guess if you can put someone's name there, it's "who" and if not it's "whom"

ex. Kristi left the roller skates on the sidewalk?