I saw Ann last weekend
Did i see Ann last weekend?
Who saw Ann last weekend?
What did I do last weekend?
I saw Ann last weekend, didn't I?
They were playing football at 4 o'clock yesterday
Were they playing football at 4 o'clock yesterday?
What were they playing football at 4 o'clock yesterday?
Who were playing football at 4 o'clock yesterday?
They were playing football at 4 o'clock yesterday, weren't they?