Conditional sentences
1. Type I: Real conditional sentences.
If + S + V(present), S + will/ shall + V(infinitive)
Eg: 1. If I am free, I will come to see you tomorrow
2. If you have finished your letter, I will post it
Note: mệnh đề chính có thể dùng thì hiện tại đơn, thì hiện tại tiếp diễn, thì hiện tại hoàn thành để diễn tả
một sự thật hiển nhiên hay quy luật của tự nhiên.
Eg: If you mix blue and red, you get purple.
2. Type II: Unreal conditional sentences at present.
If + S + V(past), S + would/ should + V(infinitive)
Note: were được sử dụng trong tất cả các câu điều kiện loại II
Eg: 1. If I were you, I would work harder
2. What would you do if you lived in Paris now?
3. Type III: Unreal conditional sentences in the past.
If + S + had + PII(past perfect), S + would/ should/ could + have + PII
Eg: 1. If I had gone there, I would have met him.
2. If she had had enough money, she would have bought that car.
4. Unless = If not
Unless we start at once, we will be late = If we don't start at once, we will be late.
Unless you study hard, you won't pass the exams = If you don't study hard, you won't pass the exams.
Eg: 1. If I had taken my mother’s advice, I wouldn’t be ill today.
2. If she had revised the lessons well, she would do the test easily now.
5. Inversion in conditionals
If I were the president, I would build more hospitals = Were I the president, I would build more
hospitals.
Were + S + , S + would + V(bare)
If I had taken his advice, I would be rich now = Had I taken his advice, I would be rich now.
Had + S + PII , I + would + V(bare)
If He had learned hard, he would have passed the final exam = Had he learned hard, he would have
passed the final exam.
Had + S + PII , S + would have + PII

9. If gravity, the pull of the earth, is zero, everything
A. will float B. would be floating C. floated D. would float
10. If an object is let off in the cabin of a spaceship, it …………….
A. floated B. is floating C. will float D. would float
11. We would save thousands of lives if the remedy for the flu.
A. we find out B. we found
C. we will find D. we had not found out
12. If you will study harder, you will surely pass the coming exams with good results.
A B C D
13. If I am 10 centimeter taller, I would play basketball.
A B C D
14. If I were you, I will go to the dentist’s and have the tooth checked.
A B C D
15. If the weather weren’t too bad, we would to go swimming
A B C D
16. If the doctors could find in the remedy, a lot of people would be saved.
A B C D
17. If he bought that house now, she ran out of money.
A B C D
18. If he weren’t too old, he would apply to the job as a war reporter.
A B C D
19. What you would do if you could speak French well?
A B C D
20. If I had money, I will buy a car.
A B C D
21. If we don’t stop to destroy forests, soon there will be no forest left on the earth.
A B C D
22. If we will reduce the speed of population growth, there will be less presure on the earth.
A B C D
23. If we do nothing for preserve their habitat, some species will become extinct.

C. If I were not oo old, I would apply for that job. D. If I am not too old, I will apply for that job.
32.I don t have enough money with me now; otherwise I will buy that coat.’
A. If I didn’t have enough money with me now, I would buy that coat.
B. If I had enough money with me now, I would buy that coat.
C. If I had enough money with me now, I wouldn’t buy that coat.
D. If I didn’t have enough money with me now, I wouldn’t buy that coat.
33.It s raining and they can t go camping in the mountain.’ ’
A. If it was raining, they could go camping in the mountain.
B. If it isn’t raining, they could go camping in the mountain.
C. If it wasn’t raining, they could go camping in the mountain.
D. If it is raining, they could go camping in the mountain.