whom

1. (interrogative) What person or people; which person or people.Examples: "Whom did you ask?"; "“Oh?” she said. “So you have decided to revise my guest list for me? You have the nerve, the – the –” I saw she needed helping out. “Audacity,” I said, throwing her the line. “The audacity to dictate to me who I shall have in my house.” It should have been “whom”, but I let it go. “You have the –” “Crust.” “– the immortal rind,” she amended, and I had to admit it was stronger, “to tell me whom” – she got it right that time – “I may entertain at Brinkley Court and who” – wrong again – “I may not.”"formalinterrogative

2. (interrogative) What person or people; which person or people.Examples: "To whom are you referring?"; "With whom were you talking?"; "The stories did not seem to me to touch life. They were plainly intended to have a bracing moral effect, and perhaps had this result for the people at whom they were aimed."formalinterrogative

3. (relative) Used to refer to a previously mentioned person or people.Examples: "That is the woman whom I spoke to earlier. (defining)"; "Mr Smith, whom we all know well, will be giving the speech. (non-defining)"; "He's a person with whom I work (defining)"formalrelative

4. (fused relative, archaic outside set patterns) The person(s) whom; whomever.Examples: "To whom it may concern, all business of John Smith Ltd. has now been transferred to Floggitt & Runne."formal

5. (informal, especially non-US) Also used with names of collective nouns that are groups of people, especially singularly-named musical groups or sports teams.Examples: "Whom was Lemmy bassist for? Motörhead!"formalinformal