1. What were you doing when the accident happened?
2. Daisy arrived at Susan's house at 9:00 pm yesterday.
3. At this time yesterday, Jennifer was not watching TV.
4. The Titanic was crossing the Atlantic when it struck an iceberg.
5. Last night, while I was doing my homework, Angela called me.
6. At this time yesterday, were you reading a magazine?
7. We were talking when the teacher came into the class.
8. I didn't have dinner with them at 8 pm yesterday.
9. Last Sunday, while we were camping, it started to snow.
10. The lady was walking when she suddenly fell on the floor.

Exercise II:

1. They came back home after they had finished their work.
2. She said that she had met Mr. Bean before.
3. Before he went to bed, he read a novel.
4. He told me he had not worn such kind of clothes before.
5. When I came to the stadium, the match had started.
6. Before she listened to music, she did her homework.
7. Last night, Peter went to the supermarket before he went home.

1. What were you doing when the accident happened?
2. Daisy arrived at Susan's house at 9:00 pm yesterday.
3. At this time yesterday, Jennifer wasn't watching TV.
4. The Titanic struck an iceberg.
5. Last night, while I was doing my homework, Angela called me.
6. At this time yesterday, were you reading a magazine?
7. We were talking when the teacher came into the class.
8. I didn't have dinner with them at 8 pm yesterday.
9. Last Sunday, while we were camping, it started to snow.
10. The lady was walking when she suddenly fell on the floor.

Cho dạng đúng của động từ trong ngoặc:

1. They (come) came back home after they (finish) finished their work.
2. She said that she (meet) had met Mr. Bean before.
3. Before he (go) went to bed, he (read) read a novel.
4. He told me he (not/wear) hadn't worn such kind of clothes before.
5. When I came to the stadium, the match (start) had started.
6. Before she (listen) listened to music, she (do) did homework.
7. Last night, Peter (go) went to the supermarket before he (go) went home.