`16.` have studied 

`-` for 7 years `-` HTHT

`17.` didn't go

`-` last Sunday `-` QKĐ

`18.` Did she get

`-` last year `-` QKĐ

`19.` have just realized

`-` just `-` HTHT

`20.` did you do `-` did

`-` last night `-` QKĐ

`21.` have worked

`-` for three years `-` HTHT

`22.` Thiếu

`23.` haven't met

`-` since her birthday `-` HTHT

`24.` got`-` had 

`-` yesterday `-` QKĐ

`_______________________`

`@` QKĐ:

`(+)`  S + V2/ed + O

`(-)` S + didn't + V_inf  + O

`(?)` Did + S +  V_inf + O?
`@` HTHT:
`(+)` S + has/have + V3/ed + O

`(-)` S + has/have + not + V3/ed + O

`(?)` Has/Have + S + V3/ed + O?

`16.` have studied 

`17.` didn't go

`18.` did she get

`19.` have just realized

`20.` did you do `-` did

`21.` have worked

`22.` Xem lại đề

`23.` haven't met

`24.` got `-`  had 

`___________________________________`

`***` QKD : 

`(+)`  S + was/ were + O.

 S + V-ed/ V_{(bất quy tắc)} + O.

`(-)`  S + was/were not + Object/Adj.

 S + did not + V (nguyên thể)

`(?)`  Was/Were+ S + Object/Adj?

 Did + S + V

`***` HTHT :

`(+)` S + have/ has + VpII

`(-)` S + have/ has + not + VpII

`(?)` Have/ Has + S + VpII +… ?