1. Have they just fastened the safety belts? What have they just fastened? Why have they just fastened the safety belts? Who has just fastened the safety belts?
2. Does Susan usually travel by bus? How does Susan usually travel? Where does Susan usually travel by bus? Who usually travels by bus?
3. Did her friends travel by bus last year? When did her friends travel by bus? How did her friends travel last year? Who travelled by bus last year?
4. Will David go to Turkey by ship? How will David go to Turkey? Where will David go by ship? Who will go to Turkey by ship?
2. I didn't hear a strange noise. Did I hear a strange noise?
3. She didn't think it over. Did she think it over?
4. The police didn't catch the criminal. Did the police catch the criminal?
5. It wasn't a terrible accident. was it a terrible accident?
6. He didn't hide the keys. Did he hide the keys?
7. She didn't find a ring. Did she find a ring?
8. Nick didn't break his leg. Did Nick break his leg?
9. Your purse wasn't on the table. Was your purse on the table?
10. They didn't fly to Washington. Did they fly to Washington?
11. They weren't at the cinema a week ago. Were they at the cinema a week ago?
12. Mary didn't lay the table. Did Mary lay the table?
13. His wife didn't forgive him. Did his wife forgive him?
14. It didn't happen last night. Did it happen last night?
15. Tom didn't decide to sell his car. Did Tom decide to sell his car?