1. I did not see him last Monday.
2. Up to the present, we have written almost every lesson in the book.
3. How many times have you seen him since he went to Edinburgh?
4. Mary has lost her hat, and she has been looking for it until now.
5. I have read the novel written by Jack London several times before.
6. He has been writing a book since last year.
7. Mr. Green has taught English in this school since he graduated from the university in 1986.
8. My father has not smoked for 5 years.
9. How long have Bob and Mary been married?
10. She won the gold medal in 1986.

• I didn't see him last Monday.
• Up to the present, we have written almost every lesson in the book.
• How many times have you seen him since he went to Edinburgh?
• Mary has lost her hat, and she has been looking for it until now.
• I have read the novel written by Jack London several times before.
• He has written a book since last year.
• Mr. Green has taught English in this school since he graduated from the university in 1986.
• My father hasn't smoked for 5 years.
• How long have Bob and Mary been married?
• She won the gold medal in 1986.

1. didn't see (DHNB quá khứ đơn: last Monday)

2. have written (DHNB hiện tại hoàn thành: Up to the present)

3. have you since (DHNB hiện tại hoàn thành: since)

4. has lost/ has looked (DHNB hiện tại hoàn thành: until now)

 5. have read (DHNB hiện tại hoàn thành: several times)

6. has written (DHNB hiện tại hoàn thành: since)

. 7. has taught (DHNB hiện tại đơn: since)/ graduated ( Sau "since" mệnh đề chia quá khứ)

8.. hasn't smoked (DHNB hiện tại hoàn thành: for 5 years).
 9. have ... been ( How long+ thì hiện tại hoàn thành)

 10. won (DHNB quá khứ đơn: in 1986)