1.Did he buy a new car?
What did he buy?
He didn't buy a new car.
2.Can she come tomorrow?
When can she come?
She can't come tomorrow.
3.Were they here yesterday?
When were they here?
They weren't here yesterday.
4.Must he leave early?
Why must he leave early?
He mustn't leave early.
5.Did he give you a pen?
What did he give you?
He didn't give you a pen.
6.Does he live next door?
Where does he live?
He doesn't live next door.
7.Do you know him well?
Who do you know well?
You don't know him well.
8.Has he find his pen?
What has he find?
He hasn't find his pen.
9.Did you see that film?
What did you see>
You didn't see that film.
10.Did he arrive at two o'clock?
When did he arrive at?
He didn't arrive at two o'clock.