Chia các động từ trong ngoặc ra thì simple past hoặc present perfect:
1) We (studied)...a very hard lesson the day before yesterday........
2) We (have studied)............almost every lesson in this book so far.....
3) We (have never watched)......that television program.......
4) We (watched).....an interesting program on television last night...
5) My wife and I........(had travelled) by air many times in the past
6) My wife and I (travelled).......... to Mexico by air last summer
7) I (have read)......that novel by Hemingway sevaral times before.
8) I (read).....that novel again during my last vacation.
9) I (had).....a little trouble with my car last week.
10) However, I (have)..... no trouble with my car since then.
(​Thì hiện tại hoàn thành)