`9)` had forgetten 

`10)` had studied 

`11)` hadn't rained

`12)` hadn't paid

`13)` hadn't done

`14)` hadn't eaten

`15)` hadn't brought

`16)` hadn't visited

`17)` hadn't met

`18)` hadn't had

`19)` hadn't used

`20)` hadn't studied

`(**)` Cấu trúc thì QKHT (dùng để diễn tả hành động xảy ra trước một hành động khác trong quá khứ):

`(+)` S + had + V3/Ved

`(-)` S + hadn't + V3/Ved

`(?)` Had + S + V3/Ved..?

Note: Các câu trên đều có 1 vế đã chia QKĐ tức có hành động xảy ra rồi `=>` vế còn lại là QKHT

`9.` had forgotten

`10.` had studied

`11.` had not rained

`12.` had not paid

`13.` had not done

`14.` had not eaten

`15.` had not brought

`16.` had not visited

`17.` had not met

`18.` had not had

`19.` had not used

`20.` had not studied

`_________________________`

`@` QKHT:

`(+)` S + had + V3/ed + O

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

`(?)` Had + S + V3/ed + O?