`1`. Ba last visited his aunt when he went abroad.

hoặc: The last time Ba visited his aunt when he went aboard.

`-` Cấu trúc: S+ have/ has+ not+ Vpp+...+ since+ QKĐ

`=` S+ last+ Ved/ V2+...+ when+ QKĐ

`=` The last time+ S+ Ved/ V2+...+ when+ QKĐ

`2`. If she had put her wallet in the bag, she wouldn't have lost it.

`-` Câu điều kiện loại `3`: Không có thật ở QK

`+` If-clause: chia QKHT

`+` Main clause: would/ should/ might/ could+ have+ Vpp

`3`. The more polluted air we breathe, the worse our health gets

`-` So sánh kép: The+ adj ( ss hơn)+ ( N)+ SVO, the+ adj ( ss hơn)+ ( N)+ S1V1O1

`4`. John apologized Patrick for being late.

`-` apologize sb for Ving: xin lỗi ai về việc gì

`1`

`@` Ba last visited his aunt when he went abroad .

`@` The last time Ba visited his aunt was when he went abroad .

`-` S + last + V(quá khứ) + O + time `=` The last time + S + V(quá khứ) + O + time : Lần cuối ai đó làm gì là khi nào .

`2` If she had put her wallet in the bag , she wouldn't have lost it .

`-` Điều kiện loại `3` : If + S + had + V3/Vpp + O , S + would/could + have + V3/Vpp + O .

`3` The more polluted air we breathe , the worse our health gets .

`-` So sánh kép : The + so sánh hơn + S + V , The + so sánh hơn + S + V .

`4` John apologized Patrick for being late .

`-` S + apologize + for + V_ing + O : Ai đó xin lỗi vì điều gì .