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 QKĐ (V: to be)

(+) S + was/were + ... 

(-) S + was/were + not ... 

(?) Was/Were + S ... ? 

S số ít, I, he, she, it + was

S số nhiều, you, we ,they + were

Công thức thì QKĐ (V: thường)

(+) S + V2/ed 

(-) S + didn't + V1 

(?) Did + S+ V1?

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

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

1. Have you taken 

DHNB: before (HTHT)

2. came 

DHNB: ago (QKD)

3. was 

4. Have you been 

DHNB: before (HTHT)

5. visited

DHNB: in 2012 (QKD)

6. didn't see

7. was 

8. read 

DHNB: last night (QKD)

9. Have you met 

`color{orange}{~MiaMB~}`