Câu Điều Kiện trong Tiếng Anh: Cấu Trúc, Cách Dùng Và Đảo Ngữ

Câu điều kiện loại 1, 2, 3 được dùng để diễn tả điều kiện có thể xảy ra, tình huống trái với hiện tại hoặc sự việc không có thật trong quá khứ. Ngoài if, người học cần nắm vững cách dùng unless, or, otherwise và các dạng đảo ngữ câu điều kiện.

Ký hiệu: Vbare = động từ nguyên thể không “to”; PII = quá khứ phân từ.

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I. Câu điều kiện loại 1 – The First Conditional

1. Connectives

If / Unless / Or / Otherwise

2. Form – Cấu trúc

If + S + V(s/es), S + will/won’t + Vbare.
　　　　　　　　　　 can/can’t + Vbare.

Ví dụ:

• If you study hard, you will pass the examination.
• If it rains tomorrow, we won’t go on a picnic.
• If you finish early, you can leave the classroom.

3. Use – Cách dùng

Câu điều kiện loại 1 diễn tả một tình huống có thật hoặc có khả năng xảy ra ở hiện tại hay tương lai.

• If Nam leaves now, he will catch the last bus.
• If you don’t wear a coat, you may feel cold.

4. Unless – Trừ khi, nếu không

Unless = If … not

Unless + S + V(s/es), S + will/won’t + Vbare.

• If you don’t hurry, you will miss the bus.
  → Unless you hurry, you will miss the bus.
• If she studies hard, she will pass the test.
  → Unless she studies hard, she won’t pass the test.

Lưu ý: Không dùng thêm dạng phủ định ngay sau unless.

5. As long as – Miễn là

As long as + S + V(s/es), S + will/can + Vbare.

• You can borrow my bike as long as you ride carefully.
• We will support you as long as you follow the rules.

6. In case – Phòng khi

Mệnh đề chính + in case + S + V(s/es).

• Please bring an umbrella in case it rains.
• Take some food in case you feel hungry later.

7. Or / Otherwise – Nếu không thì

Cấu trúc này thường được dùng để đưa ra lời nhắc nhở hoặc cảnh báo.

Mệnh lệnh + or/otherwise + S + will + Vbare.

• Hurry up, or you will miss the last bus.
• Wear your helmet; otherwise, you may get seriously injured.

Câu tương đương:

• If you don’t hurry up, you will miss the last bus.
• Unless you hurry up, you will miss the last bus.

8. Đảo ngữ câu điều kiện loại 1

Bỏ if và đưa should lên trước chủ ngữ.

Should + S + Vbare, S + will/can + Vbare.

• Should you need any help, please call me.
• Should the weather improve, we will continue our journey.

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II. Câu điều kiện loại 2 – The Second Conditional

1. Khái niệm

Câu điều kiện loại 2 diễn tả một tình huống không có thật hoặc khó xảy ra ở hiện tại và tương lai. Cấu trúc này cũng thường được dùng để đưa ra lời khuyên.

2. Form – Cấu trúc

If + S + V2/ed, S + would/wouldn’t + Vbare.
　　　　　　　　 could/couldn’t + Vbare.

Với động từ to be, thường dùng:

If + S + were/weren’t, S + would/could + Vbare.

Ví dụ:

• If I had enough money, I could buy this book.
• If she knew the answer, she would tell us.
• If I were you, I wouldn’t accept that offer.
• If he weren’t so busy, he could join the trip.

3. Unless trong câu điều kiện loại 2

Unless + S + V2/ed, S + would/wouldn’t + Vbare.

• Unless he tried harder, he wouldn’t make progress.
• Unless she practised regularly, she couldn’t improve her pronunciation.

4. Đảo ngữ câu điều kiện loại 2

a. Với were

Were + S + N/Adj, S + would/could + Vbare.

• Were I you, I would apologise to her.
• Were she more careful, she wouldn’t make so many mistakes.

b. Với were to

Were + S + to + Vbare, S + would/could + Vbare.

• Were he to study harder, he could pass the examination.
• Were they to arrive early, we would start immediately.

c. Với were it not for

Were it not for + N/cụm N, S + would/could + Vbare.

• Were it not for your support, I couldn’t complete this project.

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III. Câu điều kiện loại 3 – The Third Conditional

1. Khái niệm

Câu điều kiện loại 3 diễn tả một tình huống không có thật trong quá khứ và kết quả trái ngược với điều đã xảy ra. Cấu trúc này thường thể hiện sự tiếc nuối hoặc trách móc.

2. Form – Cấu trúc

If + S + had/hadn’t + PII, S + would/wouldn’t + have + PII.
　　　　　　　　　　　　　　　　 could/couldn’t + have + PII.

Ví dụ:

• If she had got up earlier, she wouldn’t have missed the bus.
• If we hadn’t left home late, we could have arrived on time.
• If Linda had known about the meeting, she would have attended it.

3. Unless trong câu điều kiện loại 3

Unless + S + had + PII, S + would/wouldn’t + have + PII.

• Unless you had helped me, I wouldn’t have finished the work.
• Unless she had warned us, we couldn’t have avoided the danger.

4. Đảo ngữ câu điều kiện loại 3 với Had

Bỏ if và đưa had lên trước chủ ngữ.

Had + S + PII, S + would/could + have + PII.

• Had she studied harder, she would have passed the examination.
• Had we left earlier, we could have caught the train.

Với câu phủ định:

Had + S + not + PII, S + would/could + have + PII.

• Had Tom not stayed up late, he wouldn’t have overslept.

5. Đảo ngữ với Had it not been for

Had it not been for + N/cụm N, S + would/could + have + PII.

Cấu trúc này có nghĩa là nếu không nhờ, nếu không vì, tương đương với If it hadn’t been for.

• Had it not been for your help, I would have failed the examination.
• Had it not been for the heavy rain, we could have arrived earlier.

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Ghi nhớ nhanh ba loại câu điều kiện

• Loại 1: Điều kiện có thể xảy ra
  If + hiện tại đơn, will/can + Vbare
• Loại 2: Điều kiện không có thật ở hiện tại
  If + quá khứ đơn, would/could + Vbare
• Loại 3: Điều kiện không có thật trong quá khứ
  If + had + PII, would/could have + PII

BÀI TẬP ÁP DỤNG CÂU ĐIỀU KIỆN LOẠI 1, 2, 3

Bài 1. Chọn đáp án đúng A, B, C hoặc D

1. If you leave home now, you __________ the early bus.

A. catch  B. will catch  C. would catch  D. would have caught

2. Unless Jane __________ more carefully, she will make another serious mistake.

A. works  B. worked  C. had worked  D. would work

3. Were I in your position, I __________ that expensive offer immediately.

A. refuse  B. will refuse  C. would refuse  D. would have refused

4. Had Peter checked the address, he __________ at the wrong building.

A. won’t arrive  B. wouldn’t arrive  C. wouldn’t have arrived  D. hadn’t arrived

5. Should anyone __________ further information, please contact our school office.

A. needs  B. needed  C. need  D. had needed

6. If the driver had noticed the warning sign, he __________ sooner.

A. stops  B. will stop  C. would stop  D. would have stopped

7. Hurry up, or you __________ the beginning of the performance.

A. miss  B. will miss  C. would miss  D. would have missed

8. If I __________ enough free time, I would learn another language.

A. have  B. had  C. will have  D. had had

9. Had it not been for your directions, we __________ the hotel.

A. won’t find  B. wouldn’t find  C. wouldn’t have found  D. hadn’t found

10. Unless they had taken a shortcut, they __________ before dark.

A. won’t arrive  B. wouldn’t arrive  C. hadn’t arrived  D. wouldn’t have arrived

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Bài 2. Viết lại câu sao cho nghĩa không đổi, sử dụng từ cho sẵn

1. Study harder, or you will fail the final examination.
   (If)
   → …………………………………………………………………………………………………………….
2. If you don’t leave immediately, you will miss the last train.
   (Unless)
   → …………………………………………………………………………………………………………….
3. Keep your receipt, or you won’t be able to exchange the product.
   (If)
   → …………………………………………………………………………………………………………….
4. If you need any further assistance, please contact the receptionist.
   (Should)
   → …………………………………………………………………………………………………………….
5. If I were in your position, I wouldn’t reject this opportunity.
   (Were)
   → …………………………………………………………………………………………………………….
6. If Anna had set her alarm, she wouldn’t have overslept.
   (Had)
   → …………………………………………………………………………………………………………….
7. Without your support, we couldn’t have completed the project on time.
   (Had it)
   → …………………………………………………………………………………………………………….
8. If you don’t wear protective gloves, you may burn your hands.
   (Or)
   → …………………………………………………………………………………………………………….
9. If the company reduced its prices, more customers would buy its products.
   (Were)
   → …………………………………………………………………………………………………………….
10. If the firefighters hadn’t arrived quickly, the entire building would have burned down.
    (Had)
    → …………………………………………………………………………………………………………….

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ĐÁP ÁN

Đáp án Bài 1

1. B. will catch
2. A. works
3. C. would refuse
4. C. wouldn’t have arrived
5. C. need
6. D. would have stopped
7. B. will miss
8. B. had
9. C. wouldn’t have found
10. D. wouldn’t have arrived

Đáp án Bài 2

1. If you don’t study harder, you will fail the final examination.
2. Unless you leave immediately, you will miss the last train.
3. If you don’t keep your receipt, you won’t be able to exchange the product.
4. Should you need any further assistance, please contact the receptionist.
5. Were I in your position, I wouldn’t reject this opportunity.
6. Had Anna set her alarm, she wouldn’t have overslept.
7. Had it not been for your support, we couldn’t have completed the project on time.
8. Wear protective gloves, or you may burn your hands.
9. Were the company to reduce its prices, more customers would buy its products.
10. Had the firefighters not arrived quickly, the entire building would have burned down.