1. had been playing
2. had been working
3. had been waiting
4. had been drinking
5. had been running
6. had been raining
7. had been traveling
8. had been writing
9. had been playing
10. had been working
11. Had been she
12. had been waiting
13. had been fighting
14. had been crying
15. had been learing
→ Tất cả các câu trên đều sử dụng thì quá khứ hoàn thành tiếp diễn với cấu trúc câu
(+): S + had + been + V-ing
(-): S + hadn't + been+ V-ing
(?): Had + S + been + V-ing?