`1.` No city in VN is bigger than Ho Chi Minh city

`=>` So sánh hơn với tính từ ngắn

`=>` S + tobe + adj-er + than + ..

`2.` If you don't turn unwanted lights off, you will waste a lot of electricity.

`=>` Câu điều kiện loại `1`:

`=>` If + S + Vs/es, S + will + V + ...

`3.` It's fun to learn about recycling

`=>` S + tobe + N + to V

`4.` I didn't need to recessang for me to finish my homework yesterday

`=>` S + did(not) + need to V + ...: không cần

`1`.No cities in Viet Nam is bigger than Ho Chi Minh City

`\rightarrow` So sánh hơn : S1 + is / am / are + adj-er / more adj + than + S2

`2`.If you don't turn unwanted lights off , you will waste a lot electricty

`\rightarrow` CĐK Loại `1` : Diễn tả hành động có thật ở Hiện tại

`-` If - clause : Thì HTĐ : S + Vs / es

`-` Main - clause : Thì TLĐ : S + will + V

`3`.It's fun to learn about recycling

`\rightarrow` It is ( not ) + adj + to do sth : Như thế nào để làm gì

`4`.I didn't need to finish my homework yesterday

`\rightarrow` need + to do sth : Cần làm gì

`\text{# Kirigiri}`