This is one of the elements of English grammar that has always thrown me. I usually say “Who” regardless, because I think constructions like “To whom have you been speaking” sound ridiculous.
But now my Oxford Seminar course has given me a great test, so at least I’ll know if I’m incorrect, and then I can just be brazen about it.
While whom is sometimes disregarded as antiquated British English, it is actually the object case for the pronoun who. Although native English speakers often use who for both the subject and object cases of the pronoun, this is not strictly correct.
Consider the following question:
Who opened the door? or Whom opened the door?
An appropriate response to the question is “He opened the door.” As a subject-case pronoun was used in the response, the question should be posed “Who opened the door?”.
So, did you get that?
If I have a question like “Who opened the door?”, to test my “who/whom” choice, I would think about the answer. In this case “Him opened the door” would not work. The correct statement would be “He opened the door.”
He –> Who
Him –> Whom (notice that “m” ending)
So here’s a test:
Who/Whom did I give my letter to?
Hint: The answer is “her.” I gave my letter to her. So “Whom” would be correct for my question—although I would never say this outside of an English class because it sounds ridiculous to my commoner’s ear.
“To whom did I give the letter?”
Nope, I’m still going to say: Who did I give the letter to?