Duwhaaa???

I hate that expression. If you're talking to somebody in the South and they don't understand you or didn't catch what you were saying, they'll say, "Duwhaaa?". I'm not sure how you properly spell it but this is my best guess. It's short for "do what?" Someone from the northeast might say, "Huh?" or something similar. And it doesn't matter what class of people or how educated they are, they all say "duwhaaa" as if it's hard wired in their brain. It just makes people sound less intelligent than they often really are.