He has written a long letter, hasn't he?
Has he written a long letter?
Has he written a long or a short letter?
Who has he written a long letter?
What kind of letter has he written?
What has he written?
Why has he written a long letter?
Has he or she written a long letter?
They have taken the books from the table, haven't they?
Who has taken the books from the table?
Have they taken the books from the table?
Have they taken the books or the pen from the table?
Have they taken the books from the table or from the shelf?
Why have they taken the books from the table?
What have they taken from the table?
Where have they taken the books from?