When to use who or whomWho: 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.The subject in a sentence refers to the person or thing carrying out an action. In this example the aunt is thesubject since she was the one who spoke to them.The object in a sentence refers to the person or thing that receives the action of the verb. In this example thepeople the aunt spoke to is the objectNote: "which" is not used for people