Answer: Who should be used to refer to the subject of a sentence. Whom should be used to refer to the object of a verb or preposition.
Explanation: In a sentence, who is used as a subject. 2 examples are:
- Who would like to go on vacation?
- Who made these awesome quesadillas?
Whom is used as the object of a verb or preposition. 2 examples are:
- To whom was the letter addressed?
- Whom do you believe?
