N là negative còn I là interrogative nha
1. N: They weren't in Rio last summer.
I: Were they in Rio last summer?
2. N: We didn't do our exercise this morning.
I: Did you do your exercise this morning?
3. N: My parents didn't come to visit me last July.
I: Did your parents come to visit you last July?
4. N: The hotel wasn't very expensive.
I: Was the hotel very expensive?
5. N: I didn't have a bicycle when I was young
I: Did you have a bicycle when you were young?
6. N: The children didn't go to the zoo yesterday.
I: Did the children go to the zoo yesterday?