Помогите с упражнением по английскому , пожалуйста . Хотя бы некоторые предложения

1. had arrived
2. had left
3. had seen
4. had built
5. had graduated
6. has to be ready
7. had learnt
8. will have seen
9. who will have prepared
10. hadn't worked
11. had taken a part
12. will have spent