Confused by who and whom?

Try remembering this little rule:

he = who

him = whom

If you aren’t sure which to use, insert he/him in the sentence.  For example:

“Who/Whom should I call?”

Would the answer be:

“I will call he.”  or  “I will call him?”  It would be the latter so the correct question would be “Whom do I call?”

“Who/Whom called you last night?”

Would the answer be: 

“He called you last night.” or “Him called you last night?”  Of course it is the first one, so the correct sentence would be “Who called you last night?”

I find this works every time.  I hope it helps you, too.