9. It was windy in Thanh Hoa last weekend.

 `@` QKĐ : S `+` was/were `+` O .

 `-` Dấu hiệu : last weekend (cuối tuần trước).

10. Learning and playing are really fun.

  `@` HTĐ : S `+` is/am/are `+` O .

11. When is his birthday?

  `@` Wh... `+` is/am/are `+` S `+` O ?

12. My birthday is on the first of June.

  `@` S `+` is/am/are `+` O .

13. I think I'm good at learning English.

  `@` good at st : giỏi ở cái gì

14. I want to learn English because I want to be an English teacher.

  `@` want to be st : muốn làm gì

15. I want to know more about the numbers.

  `@` want to V : muốn làm gì

 `-` S `+` V ( s/es ) `+` O .

`9,` It was windy in Thanh Hoa last week

`->` last week `->` QKĐ

`->` KĐ : S + was/were + O 

`->` tobe + adj

`10,` Learning and playing are really fun

`->` HTĐ - KĐ : S + am/is/are + O

`->` tobe + adj

`11,` When is his birthday ?

`->` HTĐ - NV : (Wh-questions) + am/is/are + S + O ?

`->` Tính từ sở hữu + Danh từ

`12,` My birthday is on the first of June

`->` HTĐ - KĐ : S + am/is/are + O

`->` on + ngày, tháng, năm cụ thể

`13,` I think I'm good at learning English

`->` HTĐ - KĐ : S + V-s/es/inf ...

`->` HTĐ - KĐ : S + am/is/are + O

`->` be good at doing sth : giỏi về việc gì

`14,` I want to learn English because I want to be an English teacher

`->` HTĐ - KĐ : S + V-s/es/inf ...

`->` want to do sth : muốn làm gì

`->` MĐ chỉ lý do : S + V + because + S + V

`15,` I want to know more about the numbers

`->` HTĐ - KĐ : S + V-s/es/inf ...

`->` want to do sth : muốn làm gì