11. have watched 12. wrote ( dấu hiệu: ago) 13. met (yesterday) 14. didn't go
15. was cooking 16. were you doing/ rang 17. was watching/ was reading
18. saw/ was going 19. was listening ( có thời điểm cụ thể ) 20. will she join
21. won't the students have 22. will be fine 23. written 24. talking