Chuyen de cau dieu kien

Conditional sentences
I.Type I (The real present or future conditional senntence)
Form
If Clause
Simple present
Main clause
Simple future
(Will/ shall/ can + bare- inf)

If + S +V (simple present)+ S + Will/ shall/ can + bare- inf

Eg :If you don’t study, you won’t pass your exam / If my headache disappears,we can play tennis
Usage: kiện này dùng để diễn tả một sự việc có khả năng xảy ra ở hiện tại hoặc tương lai.
Note :Mệnh đề chính : Thay cho Simple future ta có thể dùng : may/ might/can /must /should/ had better +bare inf, hay Imperative form khi muốn thể hiện sự yêu cầu, đề nghị , cho phép.....
Present simple khi chỉ một điều kiện có thực
Mệnh đề phụ :Thay cho Present tense ta có thể sử dụng Present continuous ,present perfect
Eg :If you are right, I’m wrong
If you see him tomorrow, tell him that I want to see him
II.Type II (Present unreal condition sentences)
Form:
If clause
Simple past
Main clause
Present Conditional (would/should +bare inf)

If +S +V (simple past) +S + Would /Could /Might + bare inf

Usage: Chỉ những sự việc trái với sự thực ở hiện tại hoặc tương lai
-If I had time, I would go to the beach with you this weekend.
-If she didn’t speak so quickly , I could understand her.
-If could go out to night If didn’t have to study
-If I were rich, I would travel around the would.
-She would tell, you about it if she were here
-If today were Sarturday , I could goto the beach.
* “Would be doing” thay thế cho “Would do” ở mệnh đề chính.
Eg: If I were on holiday in Doson, I would be lying in the sun now.
*”Past continuous ” có thể thay thế cho “past simple” ở mệnh đề điều kiện
Eg: If my car were working, I could drive you to the station
-Chú ý : Động từ Be ta dùng Were với tất cả các ngôi ,trong văn nói có thể dùng was với ( I, He , She , It)
3.Type III : Past unreal conditional sentence
Form:
If clause
Past perfect
Main clause
Perfect conditional (would, should,....)+ have + PII

 If +S + V (past perfect)+ S +Would /Could /Might + Have + Past Participle

Use : Điều kiện không có thực trong quá khứ để diễn tả những tình huống trái với thực tế trong quá khứ
-If I hadn’t lost my way , I would have arrived sooner.
-Ann would have sold the house if she had found the right buyer
-If I had known that you were there , I would have writen you letter.
*Note : Có thể dùng phép đảo ngữ trong Presen ureal conditional sentences nếu có were và past ureal conditional sentences .
-If Ann had found the right buyer, she would have sold the house
--->Had Ann found the right buyer, she would have sold the house.
*Mệnh đề điều kiện có thể đứng trước hoặc sau mệnh đề chính.
*”Would have been doing” có thể dùng thay thế cho “ would have done ” ở mệnh đề chính
Eg : At the time of the accident. I was sitting in the back of the car because Tom’s little boy was sitting beside him in front.If Tom’s boy hadn’t been there I would have been sitting in front
*”Had been doing” có thể dùng thay thế cho “ had done “ ở mệnh đề điều kiện
-I was wearing a seatbelt .If I hadn’t been wearing one, I’d been seriously injured.
*Trong mệnh đề điều kiện, ta có thể thay liên từ “If ” bằng “ Unless” (nếu .....không,trừ phi). “Unless” tương đương với “If not”
-If you don’t study hard, you’ll fail in the exam
--->Unless you study hard, you’ll fail in the exam
-If she doesn’t water these trees, they will die
--->Unless she water these trees, they will die.
*Khi ta đổi một câu điều kiện với từ nối “ IF ” sang “UNLESS”, nhớ lưu ý trường hợp mệnh đề “