Who is a subject pronoun; it can be the subject of a sentence: " Who was at the door?" Whom is an object pronoun. It cannot be the subject of a sentence, but it can be a direct or indirect object or the object of a preposition: "Don't ask for whom the bell tolls." Who and whom often appear in questions where the natural word order is inverted and where the words you see first are the pronouns who or whom, followed by part of the verb, then the subject, then the rest of the verb. So it isn't always easy to figure out if you should use who or whom . Is it " Who did you visit last summer?" or " Whom did you visit last summer?" To decide, follow these steps:
Those of us with long memories remember back in 2004 when Lawrence O’Donnell, then a talking head on MSNBC, flipped out on John O’Neill, head of Swift Boat Vets for Truth, and just started shouting “LIAR!” over and over again during an appearance. Television debates get heated, passions and tempers flare, but it entered the realm of unprofessional. Then there was the furious outburst on Morning Joe in 2010 and various other moments over the years suggesting that O’Donnell is one burst of gamma radiation away from becoming the Incredible Hulk when he’s angry.