.......................................................

`11,` had started

`12,` hadn't taught

`13,` had lost

`14,` hadn't used

`15,` had finished

`16,` had made

`17,` had left

`18,`  ...,the games room hadn't been built yet.

`+` Vế sau bị thiếu chủ ngữ. 

`-` Cấu trúc bị động qkht: S `+` had `+` been `+` V3/V-ed... 

`19,` had become - had married

`-` `-` `-` `-` `-` `-` `-` `-` `-` `-` `-` `-` 

${\text{Giải thích: }}$

`@` Cấu trúc quá khứ hoàn thành:

(`+`) S `+` had `+` V3/V-ed..

(`-`) S `+` hadn't `+` V3/V-ed

(`?`) Had (not) `+` S `+` V3/V-ed..?

`-` DHNB: before, after, by the time, when, by the end of + tgian trong qk, until, by,... 

`->` Diễn tả hành động xảy ra trước một hành động khác trong quá khứ (thường kết hợp với qkđ).

Quá khứ hoàn thành :

Diễn tả hành động đã xảy ra trong quá khứ và kết thúc trước một hành động quá khứ khác

`(+)` S + had + PII

`(-)` S + hadn't + PII

`(?)` Had + S + PII ?

---

11. had started 

DHNB : before the sunset

12. hadn't taught

13. had lost

14. hadn't used

DHNB : before 1492

15. had finished

QKHT + before + QKD : trước khi

16. had made

DHNB : by 6 o'clock

17. had left

DHNB : six years before

18. (Đề thiếu, không rõ ràng)

19. had become - had married