Sindhu, a lawyer friend, sent me this on chat:

You should do a post on who v. whom. VERY confusing, I say!

… to which I replied that she didn’t need to worry about it and as long as she trusted her instinct, it was just fine, but she said:

Yes, but it is important to know the difference.  At our firm, we are very particular about pristine English in mails to clients.

Since this is the first problem submitted to the Linguistrix Consulting Department, we would oblige with a quick answer. And Sindhu, since you are our first customer, it’s on the house!

As a general rule of thumb, if an educated* speaker with native or near native fluency feels confused about a grammatical rule, and if a lot of such speakers sitting together can’t resolve this over coffee, there is a very strong reason to suspect that the rule is not entirely relevant. This has certainly become the case with the whole who/whom issue, which tends to flummox people with otherwise impeccable grammar. The _rule_ is fairly straightforward—use _who_ when it’s a subject, _whom_ when it’s an object. But over the years, and when I say years, I mean centuries, it has always lain in a grey region. If you want to get some perspective, I will refer you to the MWDEU (Merriam-Webster’s dictionary of English Usage), which I recommended in a previous post. It devotes almost 2 entire pages only to this issue, and there is no point in repeating all that it says, so I will direct you to the relevant page. Please read what’s written there—it’s fairly comprehensive. One thing is clear—it’s not at all as cut-and-dried as we would hope or imagine.

The status quo is that some uses of _whom_ sound perfectly natural, others sound OK, and the rest sound outright affected and pretentious. Also, _whom_ is not in danger of extinction, but using _whom_ in all cases where you are questioning the object might make you sound very pompous. What should be used where is something I can’t advise Sindhu or her colleagues about, especially since I am not aware of what her firm considers pristine English—would splitting infinitives, ending sentences with prepositions, starting them with conjunctions, saying things like It is me, and half a dozen other mistakes-that-aren’t-really-mistakes be considered as wrong English? But if she wants a quick guide to figuring out where one should use whom (as far as the subject-object definition goes), a simple way would be to see which out of _he_ or _him_ fits in the sentence—if it’s him, go for whom. Of course, this doesn’t account for all the examples listed by MWDEU, but hey, I never said I was giving you a rule to produce natural-sounding sentences.

As a mnemonic, associate the m of whom with the m of him/them.

  • She loved him → Whom did she love?
  • I slapped him → Whom did I slap?
  • He was slapped by them → Who was slapped by whom?
I have noticed that people tend to not use whom in cases where it moves to the front of the clause due to wh-movement, but use whom if it remains in the original position. Compare:
Who did you talk to? v. You talked to whom? 
The second sentence is not grammatical as an isolated utterance, but it can still be expected to be produced in a conversation:
A: Who did you talk to?
B: So, well, I thought about your proposal and I also talked to Yoda about this…
A: Whoa! You talked to whom?

I strongly prefer this kind of usage, although, technically, it should have been whom in both cases. This is of course my personal preference. I am not making any claims about its generality.

[*I added educated here because an educated speaker is more likely to be well-versed with the _standard_ or prestige dialect of a language. Needless to say, one does not need education to acquire any and all the rules of their native dialect.]