Mary goes to the dentist twice a year.
Doesn't Mary go to the dentist twice a year?
He didn't do his homework
Didn't you do your homework? / Didn't he do his homework?
Mary is going to have lobster for lunch.
Isn't Mary going to have lobster for lunch?
Steve should eat more fruits and vegetables
Shouldn't Steve eat more fruits and vegetables?
They will be very angry
Won't they be very angry?
