+ He often buys toy cars.
- He doesn't often buy toy cars.
? Does he often buy toy cars?
Wh.? Where does he often buy toy cars?
Who.? Who often buys toy cars?
A.? Does he often buy toy cars or toy planes/
T.? He often buys toy cars, doesn't he?
+ We swim in the river every summer.
- We don't swim in the river every summer.
? Do we swim in the river every summer?
Wh.? Why do we swim in the river every summer?
Who.? Who swim in the river every summer?
A.? Do we swim in the river or in the sea every summer ?
T.? We swim in the river every summer, don't we?