A Linguistic Question

This is something I'm thinking about bringing up on the American Dialect Society list, but I'd like to do a little unscientific research before asking the bigwigs.

I find that I use the compound pronouns "who-all" and "what-all" fairly often in speech, and occasionally in writing. They feel to me like compound words - hence the hyphenation - rather than phrases. As far as meaning goes, a question like, "Who-all showed up at the party?" asks for a complete roster, where "Who showed up?" could be satisfied by naming a few notables. I use them in questions and in negative statements - "I don't know what-all that boy got up to!" - but only rarely if at all in affirmative statements. They have a definite colloquial feel to them, and actually strike me as more Southern than anything else. (My own dialect is of the "North Midlands" family, but with some Southern influence.)

So, a few questions for anyone who cares to comment. Do you use these phrases? (And what about "where-all", "how-all", "when-all"?) If you do, do they strike you as compound words or as phrases? Do you interpret their meanings differently than I do? Do you ever use them in affirmative statements? Any other thoughts any of you might offer would also be appreciated.