1. Why don’t we go to the canteen for a drink?
  What if we go to the canteen for a drink?

* Why don't we= What if we+ V: Sao không làm gì

2. I think we should take showers to save water.

I suggest taking showers to save water.

* S+ suggest+ V-ing; Ai gợi ý làm gì

3. Because Mr. Phong is sick today, he won’t go to work.

Mr. Phong is sick today, so he won’t go to work.

* Nguyên nhân+ so+ kết quả

4.They decided to say goodbye as they didn’t have things in common. 

 Because they didn’t have things in common, they decided to say goodbye

* Vì because= as

⇒ Kết quả+ because+ nguyên nhân

VI. Rewrite the sentence

1. What about going to the canteen for a drink?

=> what about Ving = why don't sb V

2. I suggest taking showers to save water

=> suggest Ving

3. Mr. Phong is sick today, so he won't go to work

=> Ông Phong thì bị ốm ngày hôm nay, vì vậy ông ấy không đi làm

4. They decided to say goodbye because they didn’t have things in common.

=> because = as