They are absent from the lesson.
They aren't absent from the lesson.
Are they absent from the lesson?
Are they or we absent from the lesson?
Who is absent from the lesson?
They are absent from the lesson, aren't they?
You come to work in time.
You don't come to work in time.
Do you come to work in time?
Do you come to work or to the party in time?
Where do you come in time?
You come to work in time, don't you?