We go to work by underground.
Do we go to work by underground?
We don't go to work by underground.
Paul was ill last weekend.
Was Paul ill last weekend?
Paul wasn't ill last weekend.
She catches the train every morning.
Does she catch the train every morning?
She doesn't catch the train every morning.
We watched tv yesterday.
We didn't watch tv yesterday.
Did we watch tv yesterday?
He will visit us tomorrow.
He won't visit us tomorrow.
Will he visit us tomorrow?