1. We /go skiing yesterday.

⇒ We went skiing yesterday.

2. you/ watch/ the men's basketball final/ TV/ last night?

⇒ Did you watch the men's basketball final on TV last night?

3. I/ not play/ badminton/ last Sunday/ because/ I/ be/ ill.

⇒ I didn't play badminton last Sunday because i was ill.

4. Sue and her friends/ do/ yoga/ the gym/ now.

⇒ Sue and her friends are doing yoga in the gym now.

5. Last week/ we/ study/ how/ surf. It/ be/ very interesting.

⇒ Last week, we studied how to surf. It was very interesting.

6. He/ usually/ play/ football/ his friends/ Saturdays.

⇒ He usually plays football with his friends on Saturdays.

7. Where/ the children/ be/ yesterday morning? They/ be/ at the swimming pool.

⇒ Where were the children yesterday morning? They were at the swimming pool.

8. His father/ teach/ him/ how/ play/ football/ a very young age.

⇒ His father taught him how to play foot ball when he was at a very young age.

Giải thích: Ở các câu 1,2,3,5,7,8 trên ta thấy có các từ yesterday, last night, last Sunday, last week, yesterday morning, at a very young age( sự việc đã kết thúc trong quá khứ) là dấu hiệu của thì quá khứ đơn nên ta áp dụng công thức của thì quá khứ đơn như sau.

* Động từ to be: 

+) S + was/ were +…

-) S + was/ were + not

?) Was/ Were + S +…?

* Động từ thường: 

+) S + V-ed(có quy tắc) hoặc V bất quy tắc +...

-) S + did not + Vinf

?) Did + S + Vinf?

Ở câu 4 ta thấy now là dấu hiệu của thì hiện tại tiếp diễn nên ta áp dụng công thức:

+) S + be + Ving.

-) S + not be + Ving

?) Be + S + Ving?

Câu 6 có trạng từ chỉ tần suất usually là dấu hiệu của thì hiện tại đơn nên ta áp dụng công thức

* Động từ to be:

+) S + am/is/are +...

-) S + am/is/are + not  +....

?) Am/is/are +...

* Động từ thường:

+) S + V es/s +...

+) S + do/does + not + Vinf +...

?) Do/does (not) + S + Vinf?

5. Last week, we studied how to surf. It was very interesting

6. He plays football with his friends every Sundays.

7. Where were the children yesterday morning? They were at the swimming pool 

8. His father taught him how to play football at a very young age

(Chúc bạn nhận đc nhiều lì xì nha)