Công thức thì QKHT

(+) S + had + V3/ed 

(-) S + had + not + V3/ed 

(?) Had + S+ V3/ed?

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, ...

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Hành động xảy ra trước --> QKHT 

Hành động xảy ra sau --> QKĐ

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

1. came / had finished 

QKD + after + QKHT 

2. had met 

S + said + (that) + S + V (lùi thì)

DHNB: before (HTHT)

HTHT --> QKHT 

3. went / had read 

Before + QKĐ, QKHT 

4. hadn't worn 

S + told + O + (that) + S + V (lùi thì)

DHNB: before (HTHT)

HTHT --> QKHT 

5. had started 

When + QKĐ, QKHT 

6. listened / had done 

Before + QKĐ, QKHT 

7. had gone / went 

QKHT + before + QKĐ

8. watched / had done

Before + QKĐ, QKHT 

`color{orange}{~MiaMB~}`

1. came ... had finished

2. had met 

3. went ... had read

4. had worn

5. had started

6. listened ... had done

7. had gone ... went 

8. watched ... had done 

 `->` Giải thích các bước giải:

   → QKĐ : 

     ` ( + ) ` S `+` Ved/p1 `+` O .

     ` ( - ) ` S `+` didn't `+` V `+` O .

    → QKHT :

     ` ( + ) ` S `+` had `+` Vp2 . 

     ` ( - ) ` S `+` had `+` not `+` Vp2 .