`1`. English is spoken all over the world.

`⇒` Cấu trúc: S + is/am/are + Vpp + by O

`2`. Because there was loud noise next to my door last night, I couldn't sleep.

`⇒` Từ because chỉ nguyên nhân

`3`. It's very important to keep the environment.

`⇒` Cấu trúc: It's + adj + to Vo

`4`. If you litter, the environment will be polluted.

`⇒` Cấu trúc: If + S + V(HTĐ), S + will + Vo

`5`. If you don't study harder, you won't pass the exam easily.

`⇒` Cấu trúc: If + S + don't + Vo, S + won't +Vo

`6`. After David had gone home, we arrived

`⇒` Cấu trúc: After + QKHT, QKĐ.

`1.` English is spoken all over the world.

Câu bị động thì hiện tại đơn: `text{S+am/is/are+V3/Ved+(by O)+...}`

`2.` Because their was loud noise next to my door last night, I couldn't sleep

because+mệnh đề: bởi vì...

`3.` It is important to keep the enviroment clean

Dùng chủ ngữ giả "it" để nói lên đặc điểm, tính chất của sự việc: It is+adj+to Vinf+...

`4.` If you litter, the enviroment will be polluted.

Câu điều kiện loại 1: If+S+V(htđ)+..., S+will/can/may/shall+Vinf+...

`5.` If you study harder, you will pass the exam easily

Câu điều kiện loại 1: If+S+V(htđ)+..., S+will/can/may/shall+Vinf+...

`6.` After David had gone home, we arrived.

Thì quá khứ hoàn thành: S+had+V3/Ved+...