Tài liệu ôn tập kiến thức môn Tiếng Anh Lớp 8 - Conditional sentences

CONDITIONAL SENTENCES
I. Câu điều kiện loại 1: 
1. Khái niệm câu điều kiện loại I.
Câu điều kiện loại I còn được gọi là câu điều kiện có thực ở hiện tại. Điều kiện có thể xảy ra ở hiện tại hoặc tương lai.
2. Cấu trúc – Công thức của câu điều kiện
If clause
Main clause
If + S + V s(es)...
S + will / can/ may + V1 (won't/can't + VI)
Ví dụ:
 If I find her address, I’ll send her an invitation. ( Nếu tôi tìm được địa chỉ của cô ấy, tôi sẽ gửi lời mời tới cô ấy) => Đổi vị trí 2 mệnh đề quan hệ:  I will send her an invitation if I find her address.)
If John has the money, he will buy a Ferrari. (Nếu John có nhiều tiền, anh ấy sẽ mua 
Các ví dụ khác cho câu điều kiện loại 1:
If Caroline and Sue prepare the salad, Phil will decorate the house.
If Sue cuts the onions for the salad, Caroline will peel the mushrooms.
Jane will hoover the sitting room if Aaron and Tim move the furniture.
If Bob tidies up the kitchen, Anita will clean the toilet.
Elaine will buy the drinks if somebody helps her carry the bottles.
II. Câu điều kiện loại 2:
1. Khái niệm:
Câu điều kiện loại 2 là câu điều kiện trái với thực tế ở hiện tại
2. Công thức: 
If clause
Main clause
If + S + V-ed /V2...
To be: were / weren't
S + would / could / should + V1 (wouldn't / couldn't + V1)
Ví dụ:
If I had a million USD, I would buy a Ferrari. (Nếu tôi có một triệu đô la, tôi sẽ mua chiếc xe đó.) ⇐ hiện tại tôi không có
If he had more time, he would learn karate. (  Nếu anh có nhiều thời gian, anh sẽ học karate.) ⇐ thời gian không có nhiều
She would spend a year in the USA if it were easier to get a green card. Cô ấy sẽ dành một năm ở Mỹ nếu dễ dàng có được thẻ xanh). ⇐ thực tế để lấy được thẻ xanh của Mỹ rất khó
If I lived on a lonely island, I would run around naked all day. (Nếu tôi sống trên một hòn đảo cô đơn, tôi sẽ khỏa thân chạy quanh cả ngày.) ⇐ thực tế bạn không có hòn đảo nào!
III. Bài tập:
Bài 1:
Chọn đáp án chứa lỗi sai cần được sửa lại:
1.       If we (A) have time (B) in the weekend, we (C) will come (D) to see  you.
2.       (A) if we had (B) known (C) that you were in hospital, we (D) would visit you.
3.       If I had (A) knew (B) his address, I (C) would (D) have told you.
4.       If I (A) am you, I (B) would (C) follow (D) his advice.
5.       He can (A) pass (B) the exam if he (C) studied (D) hard.
Bài 2:
I would repair the roof myself if I (have) _________________a long ladder.
Unless they turn that radio off, I (go) _________________mad.
If you were made redundant, what you (do) _________________?
We’ll have a long way to walk if we (run) _________________out of petrol here.
If you shake that bottle of port, it (not be) _________________ fit to drink.
If you spoke louder, your classmates (understand) _________________ you.
I’ll probably get lost unless he (come) _________________with me.
You (not have) _________________ so many accidents if you drove more slowly.
If you (wear) _________________ a false beard, nobody would have recognized you.
If she (leave) _________________ the fish here, the cat will eat it.
 ANSWER KEY:
Bài 1: 
1.       B (in=>at/on)
2.       D (would visit => would have visited)
4.       A (am => were)
5.       C (studied => studies)
BÀI 2: 
1
had
2
will go
3
would you do
4
run
5
won’t be
6
would have understand
7
comes
8
wouldn’t have
9
had worn
10
leaves
 
 
Bài 3. Chia động từ trong ngoặc.
1. If they (listen) carefully, they might hear the woodpecker.
2. If I had lain down on the sofa, I (fall) asleep.
3. Ngoc could have worked as a model if she (be) taller.
4. The soil (not/dry out) if you water the plants regularly.
5. If you (give) the young boy this stick, he’d hurt himself.
6. We (not/take) the wrong tram if Dzung had asked the policewoman.
7. If the cat hides in the tree, the dog (not/find) it.
8. The students would have solved the problem if they (use) their textbooks.
9. If he washed his feet more often, his girlfriend (visit) him more often.
10. Manh (read) the newspaper if he went by train.
Đáp án
1. listened; 2. could have fallen; 3. had been; 4. won’t dry out; 5. gave;
6. wouldn’t have taken; 7. won’t find; 8. had used; 9. would visit; 10. would read
Bài 4. Hoàn thành câu với từ cho sẵn (chú ý chia động từ)
1. If/ you/ mix/ red/ blue/ get / purple.
2. If/ Arsenal/ win/ they/ be/ top/ the league.
3. It /rain/ we / cancel / the match.
4. You / take / first bus/ you/will/ get /there on time.
5. You / need more helpers/ I /can try / get some time off work.
6. Mary might / deliver your parcel / you /ask /her.
7. I / were / 20/ I would/ travel/ world
8. Jim / lent / us / car / we / could / go / party.
9. We / would / save £3.50 a day / we didn’t / eat any lunch.
10. Burglars/ broke/ into my house/ they / find any money.
Đáp án
1. If you mix red and blue, you get purple.
2. If Arsenal wins, they’ll be top of the league.
3. If it rains, we will cancel the match.
4. If you take the first bus, you’ll get there on time.
5. If you need more helpers, I can try and get some time off work.
6. Mary might deliver your parcel if you ask her.
7. If I were 20, I would travel the world.
8. If Jim lent us his car, we could go to the party.
9. We would save £3.50 a day if we didn’t eat any lunch.
10. If burglars broke into my house, they wouldn’t find any money.
Bài 5. Hoàn thành câu với từ cho sẵn
1. If we meet at 9:30, we (to have) plenty of time.
2. Lisa would find the milk if she (to look) in the fridge.
3. The zookeeper would have punished her with a fine if she (to feed) the animals.
4. If you spoke louder, your classmates (to understand) you.
5. Dan (to arrive) safe if he drove slowly.
6. You (to have) no trouble at school if you had done your homework.
7. If you (to swim) in this lake, you'll shiver from cold.
8. The door will unlock if you (to press) the green button.
9. If Mel (to ask) her teacher, he'd have answered her questions.
10. I (to call) the office if I was/were you.
Đáp án:
1. will have; 2. looked; 3. had fed; 4. would understand; 5. would arrive
6. would have had; 7. swim; 8. press; 9. had asked; 10. would call
IV. Câu điều kiện loại 3
1. Khái niệm về câu điều kiện loại 3:
Câu điều kiện loại 3 là câu điều kiện không có thực trong quá khứ.
Điều kiện không thể xảy ra trong quá khứ, chỉ mang tính ước muốn trong quá khứ, một giả thiết trái ngược với thực trạng ở quá khứ.
2. Cấu trúc câu điều kiện loại 3
If clause
Main clause
lf +S + had + P.P
S + would / could / should + have + P.P
Ví dụ:
If the forwards had run faster, they would have scored more goals. (Nếu tiền đạo chạy nhanh hơn, họ sẽ ghi được nhiều bàn thắng hơn.)
If it had been a home game, our team would have won the match. (Nếu đó là trận đấu sân nhà, đội của chúng tôi sẽ thắng.)
If you had spoken English, she would have understood. (Nếu bạn nói tiếng Anh thì cô ấy đã hiểu)
If they had listened to me, we would have been home earlier. ( nếu họ đã nghe lời tôi, chúng ta đã về nhà sớm hơn)
I would have written you a postcard if I had had your address. (Tôi đã viết cho bạn một tấm bưu thiếp nếu tôi có địa chỉ của bạn)
If I had not broken my leg, I would have taken part in the contest. (Nếu tôi không bị gãy chân, tôi sẽ tham gia cuộc thi.)
3. Những trường hợp khác trong câu điều kiện:
a. Unless = If...not (Trừ khi, nếu...không)
Ví dụ:  If you don't study hard, you can't pass the exam. = Unless you work hard, you can't pass the exam.
4. Wish ( Ước)
a. Ước điều trái với thực tế ở hiện tại
S1 + wish + S1 / S2 + did sth / were ....
Eg : - I am old now. I wish I were younger.
 - Mr Blake doesn't have a house. He wishes he had a big house.
b. Ước điều trái với thực tế trong quá khứ
Eg : - Last night I went to the cinema. Now I am tired. I wish I hadn't gone to the cinema last night. ( Hôm qua tôi đã đi xem phim. Bây giờ tôi mệt. Tôi ước giá hôm qua mình đừng đi)
- He didn't learn hard at school. He regrets now.
Anh ta đã không học chăm chỉ khi còn ở trường. Bây giờ anh ta hối tiếc.
= - He wishes he had learned hard = He regrets not having learned / learning hard.
Anh ta ước trước kia đã học hành chăm chỉ.
* Notes : - Wish có thể được dùng như động từ want :
Eg : - I wish to visit my uncle = I want to visit my uncle.
Exercise : Rewrite the following sentences
1/ I'm afraid I haven't got time to listen to you. 
® I wish ..................................................................
2/ I have to work tomorrow (but I'd like to stay in bed) 
® I wish .....................................................
3/ What a pity Mai can't come. 
® I wish ...........................................................................................
4/ My brother regretted not learning Russian before.
 ® My brother wished ....................................
5/ I'm sorry that I asked her to stay. 
® Now I wish ..........................................................................
5. Unless
Thường dùng trong câu điều kiện loại 1
Eg : - If you don't start at once, you'll be late = You'll be late unless you start at once. 
Nếu cậu không bắt đầu ngay, cậu sẽ bị muộn. (Cậu sẽ bị muộn trừ khi cậu bắt đầu ngay)
® Unless = If not
Exercise : Rewrite the following sentences
1/ I'll only help you if you promise to try harder. 
® Unless ..........................................................
2/ The fire will go out if someone doesn't put some more coal on. 
®- Unless ..................................
3/ If you don't take care of those shoes, they won't last for long. 
®- Unless ..................................
4/ If we don't hurry, the sun will rise before we reach the top. 
® Unless ........................................
5/ If it doesn't stop raining, they will cancel the tournament. 
®- Unless..........................................
6/ The child will die if nobody sends for a doctor. 
® Unless .........................................................
V. Exercises:
Bài 1. Hoàn thành câu với từ cho sẵn
1.If it (to be) warmer, we (to go) swimming.
2. My parents (to buy) this house if the man (not/to sell) it to someone else.
3. If he (not/to fail) his driving test, his parents (to lend) him their car.
4. If my uncle (to tell) me the way to his office, I (not/to arrive) so late.
5. She (to be) at the airport if she (to read) the message carefully.
6. Lucy (not/to hurt) her foot if she (not/to drop) the old box on it.
7. If you (to use) a sharp knife, you (not/to cut) yourself.
8. If Victoria (to celebrate) her birthday at home, I (to bring) her some flowers.
9. We (to take) the train to Edinburgh if it (to run) on time.
10. If Max (not/to forget) his schoolbag, he (to give) you your USB flash drive.
Đáp án
1. If it had been warmer, we would have gone swimming.
2. My parents would have bought this house if the man had not sold it to someone else.
3. If he had not failed his driving test, his parents would have lent him their car.
4. If my uncle had told me the way to his office, I would not have arrived so late.
5. She would have been at the airport if she had read the message carefully.
6. Lucy would not have hurt her foot if she had not dropped the old box on it.
7. If you had used a sharp knife, you would not have cut yourself.
8. If Victoria had celebrated her birthday at home, I would have brought her some flowers.
9. We would have taken the train to Edinburgh if it had run on time
10. If Max had not forgotten his schoolbag, he would have given you your USB flash drive.
Bài 2: Cho dạng đúng của động từ trong ngoặc:
1. If I see him, I _____ (give) him a gift.
2. If I had a typewriter, I _____ (type) it myself.
3. If I had known that you were in hospital, I _____ (visit) you.
4. You could make better progress if you _____ (attend) class regularly.
5. If I _____ (know) his telephone number, I’d give it to you.
6. If you _____ (arrive) ten minutes earlier, you would have got a seat.
7. If he worked more slowly, he _____ (not make) so many mistakes.
8. I shouldn’t drink that wine if I _____ (be) you.
9. If I _____ (find) a cheap room, I will stay a fortnight.
10. A lot of people _____ (be) out of work if the factory closed down.
11. I (have) .. plenty of money now if I (not/spend)  so much yesterday.
12. If someone (give) .you a boat, what you (do)  ?
13. If you...........(press) CTRL + S, you...........(save) the file.
14. The children...........(be) happy if he...........(teach) them English.
15. If she...........(buy) a new hard disk, she...........(not/ lose) all data.
Đáp án:
1. will give;
2. would type;
3. would have visited ;
4. attended;
5. knew;
6. had arrived;
7. wouldn't make;
8. were;
9. find;
10. would be;
11. would have/ hadn't spent (ĐK hỗn hợp);
12. gives/ what will you do;
13. press/ save (hoặc will save);
14. would be/ taught;
15. had bought/ wouldn't have lost;
Bài 3: Bài tập chuyển sang câu điều kiện có đáp án.
1. Keep silent or you’ll wake the baby up.
→ If you don't keep silent, you will wake the baby up.
2. Stop talking or you won’t understand the lesson.
→ If.......
3. I don’t know her number, so I don’t ring her up.
→If........
4. I don’t know the answer, so I can’t tell you.
→ If ...
5. We got lost because we didn’t have a map.
→ If ....
6. Susan felt sick because she ate four cream cakes.
→..
7. Without this treatment, the patient would have died.
→.....
8. He lost his job because he was late every day.
→...
9. Peter is fat because he eats so many chips.
→.....
10. Robert got a bad cough because he started smoking cigarettes.
→....
Đáp án tham khảo (ngoài ra còn nhiều cách viết sử dụng từ ngữ khác nhau, nhưng nghĩa là không thay đổi)
2. If you keep talking, you won't understand the lesson.
3. If I know her number, I will ring her up.
4. If I know the answer, I will tell you.
5. If we had had a map, we wouldn't have got lost.
6. If Susan hadn't eaten four cream cakes, she wouldn't have felt sick.
7. If we hadn't had this treatment, the patient would have died.
8. If he hadn't been late every day, he wouldn't have lost his job.
9. If Peter ate less chips, he wouldn't be fat.
10. If Robert hadn't started smoking cigarettes, he wouldn't have got a bad cough.
Định dạng bài viết: Tiêu chuẩn
Nguyên tắc chung cần nhớ là :
Although/ though + mệnh đề
Despite / in spite of + cụm từ
Các công thức biến đổi từ mệnh đề sang cụm từ như sau:
1) Nếu chủ từ 2 mệnh đề giống nhau:
– Bỏ chủ từ ,động từ thêm ING .
Although Tom got up late, he got to school on time.
=> Despite / in spite of getting up late, Tom got to school on time.
2) Nếu chủ từ là danh từ + be + tính từ
– Đem tính từ đặt trước danh từ ,bỏ to be 
Although the rain is heavy,.
=> Despite / in spite of the heavy rain, 
3) Nếu chủ từ là đại từ + be + tính từ :
– Đổi đại từ thành sỡ hửu ,đổi tính từ thành danh từ ,bỏ be 
Although He was sick,..
=> Despite / in spite of his sickness,.
4) Nếu chủ từ là đại từ + động từ + trạng từ 
– Đổi đại từ thành sở hữu, động từ thành danh từ ,trạng từ thành tính từ đặt trước danh từ
Although He behaved impolitely,..
=> Despite / in spite of his impolite behavior ,
5) Nếu câu có dạng : there be + danh từ Hoặc : S + have + N
– Thì bỏ there be 
Although there was an accident ,..
=> Despite / in spite of an accident,
Công thức này cũng áp dụng cho biến đổi từ BECAUSE -> BECAUSE OF
BÀI TẬP 1 :
Viết lại câu không thay đổi nghĩa:
1) Although Tom was a poor student, he studied very well.
=> In spite of 
2) Mary could not go to school because she was sick.
 Because of .ð
3) Although the weather was bad, she went to school on time.
=> Despite .
4) My mother told me to go to school although I was sick.
=> In spite of .
5) Because there was a big storm, I stayed at home.
=> Because of .
6) Tom was admitted to the university although his grades were bad.
 Despite .ð
7) Although she has a physical handicap, she has become a successful woman.
=> Despite .
8) In spite of his god salary, Tom gave up his job.
=> Although.
9) Though he had not finished the paper, he went to sleep.
=> In spite of 
10) In spite of the high prices, my daughter insists on going to the movies.
=> Even though 
BÀI TẬP 2 :
1) Many people began to wearing jeans because they were cheap.
=> Because of..
2 ) Since he was careless, Tom lost the game.
=> Because of..
3) Although she behaves well, no one loves her.
Despite..
4) Because of the cold weather, the crops are late this year.
=> Because ..
5) Mary was worried because Tom was late.
=> Because of..
6) Tom walked slowly because his leg was bad.
=> Because of..
7) I came here because I want the English course.
=> Because of..
8) I went to school although it was hot.
Despite..
9) Because the dust in the room, I can’t go in.
=> Because of..
10) Because of too much smoke, We have to wear masks .
=> Because ..
ĐÁP ÁN BÀI TẬP 1 :
Viết lại câu không thay đổi nghĩa:
1) Although Tom was a poor student, he studied very well.
=> In spite of being a poor student, Tom studied very well
2) Mary could not go to school because she was sick.
 Because of ðbeing sick,Mary couldn’t go to school 
3) Although the weather was bad, she went to school on time.
=> Despite the bad weather,she went to school on time
4) My mother told me to go to school although I was sick.
=> In spite of my sickness,my mother told me to go to school
5) Because there was a big storm, I stayed at home.
=> Because of a big storm, I stayed at home
6) Tom was admitted to the university although his grades were bad.
 Despite ðTom’s bad grade,he was admitted to the university
7) Although she has a physical handicap, she has become a successful woman.
=> Despite her physical handicap,she has become a successful woman
8) In spite of his good salary, Tom gave up his job.
=> Although Tom got a good salary, he gave up his job
9) Though he had not finished the paper, he went to sleep.
=> In spite of having not finished the paper,he went to sleep
10) In spite of the high prices, my daughter insists on going to the movies.
=> Even though the prices are high, my daughter insists on going to the movies
ĐÁP ÁN BÀI TẬP 2:
1) Many people began to wearing jeans because they were cheap.
=> Because of the cheapness of jeans, many people began to wearing them
2 ) Since he was careless, Tom lost the game.
=> Because of Tom’s carelessness, he lost the game
3) Although she behaves well, no one loves her.
=> Despite her good behaviour, no one loves her
4) Because of the cold weather, the crops are late this year.
=> Because the weather is cold, the crops are late this year
5) Mary was worried because Tom was late.
=> Because of Tom’s lateness, Mary was worried
6) Tom walked slowly because his leg was bad.
=> Because of Tom’s bad leg, he walked slowly
7) I came here because I want the English course.
=> Because of wanting the English course, I came here
8) I went to school although it was hot.
=> Despite the hot weather, I went to school
9) Because of the dust in the room, I can’t go in.
=> Because there is the dust in the room, I can’t go in.
10) Because of too much smoke, we have to wear masks .
=> Because there is a lot of smoke, we have to wear masks