Who versus Whom

Who and whom are both pronouns. The difference between them is that who is a subject pronoun and whom is an object pronoun.

English sentences, in general, are made up of a subject, a verb and an object. The subject does the action, the object has the action done unto it, and the verb is the action.

Pat punched Mike - Pat is the subject, Mike the object, to punch is the verb.

He punched Mike - he is the subject, Mike is still the object, to punch is still the verb.

Pat punched him - Pat is the subject, him is the object, and to punch is still the verb.

Now. You'll notice that a different pronoun is used when the noun the pronoun replaces is the subject or object of a sentence. If the noun is the subject we say he or she. If the noun is the object of the sentence we say him or her.

And this is where who and whom come in. We use who when the answer is the subject of the sentence (he/she), and whom when the answer is the object of the sentence (him/her.)

Pat punched Mike.

Who punched Mike? He punched Mike.

Whom did Pat punch? Pat punched him.

Mary kicked Kate.

Who kicked Kate? She kicked Kate.

Whom did Mary kick? Mary kicked her.

Frank gave a ring to Mary.

Who gave Mary a ring? He gave Mary a ring.

To whom did Frank give a ring? He gave a ring to her.

Easy, really.