When does one use whom, and when does one use who?

Question

I can't remember if I have ever actually learned these.

Answer 1

"Who" is a subject, as in "Who did this?" You would use it in the same places you would use "I", "we", "he", "she", and "they".

The object is "whom", as in "To whom shall I give this?" Other objects are "me", "us", "him", and "them".

Answer 2

The distinction between “who” and “whom” is basically simple: “who” is the subject form of this pronoun and “whom” is the object form.
For example:
Who sent you that letter?
To whom should I address this letter?

Answer 3

Whom is objective case, and who is subjective. So you would use whom in the same situations as him or her and who in the same instances as he or she.

Answer 4

To whom are you refering to. Who are you speaking to .Whom is when you are asking about someone .

Answer 5

If you would be able to say 'him' then you can say 'whom'.

If you would be able to say 'he' then you can say 'who'.