* Cấu trúc : 

* If 1 : 

If + S + V(hiện tại đơn), S + will/won't + V 

* If 2 : Không có thật ở hiện tại 

If + S + V (quá khứ đơn), S + would/could + V 

- Áp dụng công thức ta có : 

`1.` had been - would have gone 

`2.` would have bought - hadn't sold 

`3.` Hadn't failed - would have lent 

`4.` had told - wouldn't have arrived 

`5.` would have been - had read 

`6.` wouldn't have hurt - hadn't dropped 

`7.` had used - wouldn't have cut 

`8.` had celebrated - would have brought 

`9.` would have taken - had run 

`10.` hadn't forgotten - would have given 

` - ` Cấu trúc câu điều kiện loại ` 3 `: 

\begin{array}{|c|c|c|}\hline \text{Mệnh đề phụ (If clause)}&\text{Mệnh đề chính}\\\hline \text{If + S + had + V3 + O}&\text{S + would + have + V3 + O}\\\hline \text{Quá khứ hoàn thành}&\text{Dạng lùi 2 thì}\\\hline\end{array}

` - ` Diễn tả những việc đã không xảy ra trong quá khứ và xác định kết quả nếu nó đã xảy ra. Thường ám chỉ sự tiếc nuối hoặc lời trách móc.

` -> ` Áp dụng:

` 1 `. had been - would have gone

` 2 `. would have bought - hadn't sold

` 3 `. hadn't fallen - would have lent

` 4 `. had told - wouldn't have arrived

` 5 `. would have been - had read

` 6 `. wouldn't have hurt - hadn't dropped

` 7 `. hadn't used - wouldn't have cut

` 8 `. had celebrated - wouldn't have brought

` 9 `. would have taken - had run

` 10 `. hadn't forgotten - would have given

- Chúc cậu học tốt.