Công thức thì HTHT 

(+) S + has/have + V3/ed 

(-) S + has/have + not + V3/ed 

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

DHNB: before, since + mốc thời gian, for + khoảng thời gian, yet, already, just,....

Công thức thì QKHT 

(+) S + had + V3/ed 

(-) S + had + not + V3/ed 

(?) Had + S+ V3/ed?

Công thức thì HTĐ (V: thường) 

S số ít, he, she, it 

(+) S + Vs/es

(-) S+ doesn't + V1 

(?) Does +S +V1?

S số nhiều, I, you, we, they

(+) S + V1 

(-) S+ don't + V1 

(?) Do + S+ V1? 

DHNB: always, usually, sometimes, often, never, seldom,....

Công thức thì HTTD 

(+) S + am/is/are + Ving 

(-) S + am/is/are + not + Ving 

(?) Am/Is/Are +S +Ving? 

DHNB: now, right now, (!), at present, at the moment,.....

Công thức thì QKTD  

(+) S + was/were + Ving 

(-) S + was/were+ not + Ving 

(?) Was/Were +S +Ving? 

Công thức thì QKĐ (V: thường) b

(+) S + V2/ed 

(-) S + didn't + V1 

(?) Did + S+ V1?

DHNB: ago, last (year, month ...), yesterday, in + năm QK, ...

-------------------------------------------------

6. are preparing 

DHNB: at the moment (HTTD)

7. has worked

DHNB: so far (HTHT)

8. hasn't smoked 

DHNB: for 5 years (HTHT)

9. arrived / had just gone 

10. have Bob and Mary been 

11. were playing 

When + QKD, QKTD

12. discovered

DHNB: ago (QKD)

13. hears

TLD + as soon as + HTD 

14. haven't received / left 

HTHT + since + QKD 

15. am having 

16. is coming 

DHNB: Hurry up! (HTTD)

17. don't eat 

18. was watching 

DHNB: at 8 last evening (QKTD)

19. Don't speak / asks

`color{orange}{~MiaMB~}`