I had a teacher in high school who said one day there was no difference between "who" and "whom." I never could figure out whether she was stupid or she just misspoke, but her statement still bothers me more than 30 years later.
Why? Because the difference between "who" and "whom" is so easy to figure out. The only reason we struggle with it in written American English is because we have become sloppy in spoken American English, rarely bothering to use "whom" where we should.
Here's how you can tell which word belongs where: "Who" is to "he" as "him" is to "whom." If you're looking for a mnemonic device, notice that "him" and "whom" both end with "m."
So when you're trying to figure out whether to use "who" or "whom," rearrange the sentence to use "he" or "him" - if you speak American English fluently, you should have no problem figuring it out.
Here are some examples, starting with what should be a perfect mnemonic device:
For _____ the Bell Tolls.
Is it "the bell tolls for he" or "the bell tolls for him"? Duh! The answer is "him," which means we use "whom."
We gave the job to Bob, _____ was clearly more educated than the other candidates.
Is it "he was clearly more educated" or "him was clearly more educated"? No brainer: The answer is "he," which means we use "him."
Let's pick on Bob just a bit more.
We gave the job to Bob, _____ we consider to be the most qualified.
This is the one that gets people. It was Bob comma who the first time, so why shouldn't it be Bob comma who this time?
This is why you have to use the "he-who, him-whom" test: Is it "we consider he to be the most qualified" or "we consider him to be the most qualified"?
The answer is "him," so we should use "whom" in this one.
© Holly A. Heyser