—used to express the action or process of thinking
Let's get one question out of the way immediately … : does Spike Lee like to cause trouble? "Hmm," he says, sighing. "Yeah, I guess you could call me an instigator." Patrick DemarchelierAs an undergraduate, I settled on history, and diplomatic history, because I had a really cool professor. I was thinking, Hmmm, I wonder how you get to be a diplomat? Julia Wilkinson
2
—used to emphasize that one has asked a question and is awaiting an answer
But tell Santa the truth now, what's the most important part to a little boy or girl? The box? The wrapping paper? Or the game that comes in the box? Hmmm? It's the present, of course. Mark Newman
3
—used to request repetition or clarification of something just said
"So tell me," I said. "To what do I owe the pleasure?" "Hmm?" "What brings you here?" David Housewright