11. I don't know the answer, so I can't tell it to you. A. If I knew the answer, I wouldn't tell it to you. B. If I knew the answer, I would tell it to you. C. If I knew the answer, I will tell it to you. D. If I had known the answer, I would tell it to you 12. "I will call the police if you don't give me back my bicycle". A. Unless you give me back my bicycle, I will call the police. B. Unless you gave me back my bicycle, I would call the police. C. Unless you don't give me back my bicycle, I will call the police. D. Unless you give me back my bicycle, I won't call the police 13. Jack is stopped by the police because he passes the speed limit. If Jack didn’t pass the speed limit, he wouldn’t be stopped by the police. If Jack passed the speed limit, he would be stopped by the police. If Jack hadn’t passed the speed limit, he wouldn’t be stopped by the police. Unless Jack didn’t pass the speed limit, he wouldn’t be stopped by the police 14. Mr.Richards lost his job because he was late every day. A. If Mr.Richards were late every day, he would lose his job. B. If Mr.Richards had been late every day, he would have lost his job. C. If Mr.Richards weren't late every day, he wouldn't lose his job. D. If Mr.Richards hadn't been late every day, he wouldn't have lost his job. 15. I don’t know French. Therefore, I can’t translate this letter for you. A. If I knew French, I could translate this letter for you. B. I wish I know French and translated this letter for you. C. If I knew French, I can translate this letter for you. D. If I know French, I could translate this letter for you.

`11.` `B`

`-` Loại `A` vì sai nghĩa, `C` và `D` sai công thức.

`12.` `A`

`13.` `A`

`-` Loại `B` và `C` vì sai công thức , `D` vì unless không cần not.

`14.` `C`

`15.` `A`

`-` Câu `11` , `13` , `14` , `15` đề bài viết ở thì Hiện Tại Đơn `->` dùng câu điều kiện loại `2` diễn tả sự việc không có thật ở hiện tại.

`-` Công thức : If + S + V(quá khứ đơn) , S would/could/... + Vinf

`-` Unless = If...not...

11. I don't know the answer, so I can't tell it to you.

A. If I knew the answer, I wouldn't tell it to you.

B. If I knew the answer, I would tell it to you.

C. If I knew the answer, I will tell it to you.

D. If I had known the answer, I would tell it to you

12. "I will call the police if you don't give me back my bicycle".

A. Unless you give me back my bicycle, I will call the police.

B. Unless you gave me back my bicycle, I would call the police.

C. Unless you don't give me back my bicycle, I will call the police.

D. Unless you give me back my bicycle, I won't call the police

13. Jack is stopped by the police because he passes the speed limit.
If Jack didn’t pass the speed limit, he wouldn’t be stopped by the police.
If Jack passed the speed limit, he would be stopped by the police.
If Jack hadn’t passed the speed limit, he wouldn’t be stopped by the police.
Unless Jack didn’t pass the speed limit, he wouldn’t be stopped by the police
14. Mr.Richards lost his job because he was late every day.
A. If Mr.Richards were late every day, he would lose his job.
B. If Mr.Richards had been late every day, he would have lost his job.
C. If Mr.Richards weren't late every day, he wouldn't lose his job.
D. If Mr.Richards hadn't been late every day, he wouldn't have lost his job.
15. I don’t know French. Therefore, I can’t translate this letter for you.
A. If I knew French, I could translate this letter for you. 
B. I wish I know French and translated this letter for you.
C. If I knew French, I can translate this letter for you.
D. If I know French, I could translate this letter for you.

*** Cần nhớ:

CT câu điều kiện loại 2:

If + thì quá khứ đơn, S would + động từ nguyên mẫu

Unless=If not