Đáp án:
Ex1. 1. play $\to$ played
2. go $\to$ went
3. watch $\to$ watched
4. write $\to$ wrote
5. read $\to$ read
6. do $\to$ did
7. swim $\to$ swam
8. wash $\to$ washed
9. sleep $\to$ slept
10. drink $\to$ drank
11. study $\to$ studied
12. teach $\to$ taught
13. sing $\to$ sang
14. cook $\to$ cooked
15. fly $\to$ flew
16. miss $\to$ missed
Ex2.
1. (-) Yesterday, I didn't go to the restaurant with a client.
(?) Did I go to the restaurant with a cilent yesterday ?
2. (-) We didn't drive around the parking lot for 10 mins to find a parking space.
(?) Did we drive around the parking lot for 20 mins to find a parking space.
3. (-) The waitress didn't tell us to come back in two hours.
(?) Did the waitress tell us to come back in two hours ?
4. (-) My cilent and I didn't slowly walked back to the car.
(?) Did my cilent and I slowly walk back to the car?
5. (-) We didn't see a small grocery store.
(?) Did we see a small grocery store?
6. (-) They didn't go to the concert last Sunday.
(?) Did they go to the concert last Sunday?
7. (-) She didn't graduate last year.
(?) Did she graduate last year?
8. (-) I didn't do my homework last night.
(?) Did I do my homework last night?
Ex3.
1. went
2. didn't drive
3. visited
5. didn't slowly walk
6. saw
7. didn't go
8. Did she get
9. bought
10. Did that boy have
Ex4.
1. was
2. was
3. weren't
4. were
5. was
6. weren't
