Ex1:
1. Did you watch ( Thì quá khứ đơn)
2. was doing ( thì quá khứ tiếp diễn )
3. watched / had washed
4. works / is spending / is learning
5. went / were having
6. doesn’t watch ( câu phủ định thì hiện tại đơn )
7. went / had called
8. rang / was taking
9. does the next train leave
10. rains ( thì hiện tại đơn )
is raining ( thì hiện tại tiếp diễn )
11. are living ( thì hiện tại tiếp diễn )
12. have known ( thì hiện tại hoàn thành )
13. was reading / was learning / was doing
14. haven’t had ( thì hiện tại hoàn thành )
Ex2:
1. The last time we went to a concert was over a year ago.
2. How long it is since you last saw Tom?
3. I had had a bath, I went to bed
4. By the time we arrived, the party had finished
5. Before she went to the post office, she had written the letter
6. When the pupils had done the experiment, they wrote the report on it
7. While I was staying in Paris last summer, I met her
8. While we were having lunch, someone rang the bell
9. She began to study Japenese 5 years ago.