Ta có cấu trúc thì quá khứ đơn 

` ( + ) ` : S + V-ed / V2

` ( - ) ` : S + didn't + V nguyên mẫu

` ( ? ) `: Did + S + V nguyên mẫu ?

Đối với tobe

` ( + ) `: S + was / were + ...

` - ` Chủ ngữ là i / he / she / it + was + ...

` -` Chủ ngữ là you /we  / they + were + ...

` ( - ) ` : S + wasn't / weren't 

` - ` Chủ ngữ là i / he / she / it + wasn't + ...

` -` Chủ ngữ là you /we  / they + weren't + ...

` ( ? ) `: Was / Were + S + ... ? 

Các dấu hiệu nhận biết thường gặp : Yesterday , last month , last night , five days ago , ... 

` 1 `: Were they happy last holiday ?
` 2 `: How did you get there ?
` 3 ` : My mother made 2 cakes ` 4 ` days ago

` 4 `: tyler visited his grandmother last month

` 5 `: Jonh went to the zoo 5 days ago

` 6 ` : My father wasn't at the office the day before yesterday

Đáp án: 

5. Were they happy last holiday ?

- vì có "last holiday" dấu hiệu thì QKĐ.

6. How did you get there?

7. My mother made two cakes four days ago.

- vì có ''four days ago'' dấu hiệu thì QKĐ.

8. Tyler visited his grandmother last month.

- vì có "last month" dấu hiệu thì QKĐ.

9. John went to the zoo five days ago.

- vì có "five days ago" dấu hiệu thì QKĐ.

10. My father wasn't at the office the day before yesterday.

- vì có "yesterday" dấu hiệu thì QKĐ.

- Dựa vào cấu trúc thì QKĐ:

$\text{(+) Khẳng định: S + Ved/V2.....}$

$\text{(-) Phủ định: S + didn't + V1...}$

$\text{(?) Nghi Vấn:  Did + S + V1 .....?}$

- Tobe:

$(+) S + was/were$

$(-) S + was/were + not....$

(?) Was / Were + S + ... ?