Ahh, the subtleties of evasive language. Alex and Allison were assigned to clean up their arts and crafts supplies in the basement. After a few minutes of banging, giggling, and crashing, I walked over to the top of the stairs.
Me: "Alex, are you guys cleaning up down there?"
Alex (confidently): "We're workin' on it, Dad!"
Me: "But are you cleaning anything?"
Alex (pause): "Uh, no."
Always ask the follow-up question.