Who Versus Whom
Like whom, the pronoun him ends with the letter M. When you're trying to decide whether to use who or whom, ask yourself if the hypothetical answer to the question would contain he or him. If it’s him, you use whom, and they both end with M.
Page 1 of 2
When you’re trying to figure out whether to use who or whom, it helps to know the difference between subjects and objects because you use who when you’re referring to the subject of a clause and whom when you’re referring to the object of a clause. In other words, who is a subject pronoun and whom is an object pronoun.
Subject and Objects
The subject of a sentence is doing something, and the object of a sentence is having something done to it.
For example, if Squiggly calls Aardvark, then Squiggly is the subject because he is the one calling, and Aardvark is the object because he is the one being called.
Squiggly is the subject because he’s taking action, and Aardvark is the object because he’s the recipient of the action.
Remember, use whom when you are referring to the object of a sentence.My guess is that when people ask about who or whom, most of the time they are really just curious about whom because that’s the less common word. You tend to look at sentences and think Is this where a need a whom? not Is this where I need a who?
For example, it is Whom did you squish? if you are trying to figure out that I squished Squiggly because whom is the one being squished—the object of the squishing.
Here’s another example: It would be Whom do you love? because you are asking about the object—the target of the love. I know, it's shocking, but Bo Diddley was being grammatically incorrect when he wrote the song "Who Do You Love?”