1.They take a book everyday.
They don't take a book.
Do they take a book?
2.They are taking book now.
They aren't taking book now.
Are they taking book now?
3.They have already taken a book.
They haven't taken a book.
Have they taken a book yet?
4.They have been taking a book for 5 years.
They haven't been taking a book since 1999.
Have they been taking a book?
5.They took a book yesterday.
They didn't take a book yesterday.
Did they take a book yesterday?
6.They were taking a book, when I came home.
They weren't taking a book from 5 till 7.
Were they taking a book at that time?
7.They had taken a book by that time.
They hadn't taken a book by 7 o'clock yesterday.
Had they taken a book by the party?
8.I think they'll take a book tomorrow.
They feel bad today they won't take a book tomorrow.
Will they take a book tomorrow?