36 . It was not until he was 5 that my son talked 

37. It was not untill midnight that we went to bed 

38. It was not until his teacher came that the boy stopped singing

39.It was not until she received his letter that she wrote to him

40.It was not until yesterday that the letter came 

- It was not until + clause/từ hoặc cụm từchỉ thời gian/... + that + mệnh đề

- Trước that là 1 mệnh đề thể phủ định và sau that là 1 mệnh đề thể khẳng định 

- Mệnh đề sau that luôn chia với thì Quá Khứ Đơn nếu mệnh đề trước tobe là was not

* Thì Quá Khứ Đơn : 

Động từ tobe : I/he/she/it + was , we/you/they + were

+) S + was/were + ... 

-) S + was/were + not + ... 

?) Was/were + S + ... ? 

Động từ thường : 

+) S + Ved/V2 + O

-) S + didn't + V nguyên + O 

?) Did + S + V nguyên + O ? 

Đáp án:

`-` It was not until + time word / phrase / clause + that + (mệnh đề QKĐ).

`-` Mệnh đề QKĐ `:` S + V2 / Ved + O.

`-` Sau  $" that "$  là một mệnh đề khẳng định. 

`36.`  It was not until he was  `5`  that my son talked.

`37.`  It was not until midnight that we went to bed.

`38.`  It was not until his teacher came that the boy stopped singing.

`39.`  It was not until she received his letter that she wrote to him.

`40.`  It was not until yesterday that the letter came.