`1`. I suggest meeting inside the center, at the cafe's corner.

`-` suggest+ Ving: đề nghị làm việc gì

`2`. It's very important to keep the environment clean.

`-` It's+ adj+ to V: Nó thì như thế nào khi làm việc gì

`3`. Unless someone puts the coal in, the fire will go out.

`-` Unless `=` If+...+ not

`4`. How about plating some trees around your house to get more fresh?

`-` Why+ trợ+ not+ S+ V? Tại sao ai đó không làm gì đó (Câu đề nghị)

`≈` How/ What+ about+ Ving? Thế còn làm gì thì sao (Câu đề nghị)

1. I suggest meeting inside the center, at tue cafe's corner.

- suggest+V_ing

2. It's very important to keep the environment clean.

- It's important to V: quan trọng để làm gì

3. Unless someone put the coal in, the fire will go out.

- unless: trừ khi/ nếu không

4. How about planting some trees around your house to get more fresh.

- how about+V_ing