1) They are in Europe now.
Are they in Europe now?
They aren't in Europe now.
2) She is clever girl.
Is she clever girl?
She isn't clever girl.
3) It is cold today.
Is it cold today?
It isn't cold today.
4) He is in his office.
Is he in his office?
He isn't in his office.
5) They are members of the country club.
Are they members of the country club?
The aren't members of the country club.