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