CHUYÊN đề bồi DƯỠNG ôn THI đại học CONDITIONAL SENTENCES ( các LOẠI câu điều KIỆN)

SỞ GIÁO DỤC VÀ ĐÀO TẠO VĨNH PHÚC TRƯỜNG THPT TRẦN NGUYÊN HÃN CHUYÊN ĐỀ BỒI DƯỠNG ÔN THI ĐẠI HỌC Tên chuyên đề : CONDITIONAL SENTENCES ( CÁC LOẠI CÂU ĐIỀU KIỆN) Người thực chuyên đề: Nguyễn Thị Ngọc Loan Chức vụ: Giáo viên Đơn vị công tác: Trường THPT Trần Nguyên Hãn- Lập Thạch- Vĩnh Phúc Đối tượng học sinh: lớp 12 Dự kiến số tiết bồi dưỡng: tiết A LÝ THUYẾT I BA LOẠI CÂU ĐIỀU KIỆN CƠ BẢN Conditional sentence Type 1: Present Real Conditional ( Điều kiện có thật tại/ tương lai) Câu điều kiện có thật câu mà người nói dùng để diễn đạt hành động tình thường xảy (thói quen) xảy (trong tương lai) điều kiện mệnh đề thoả mãn Nếu nói tương lai, dạng câu sử dụng nói đến điều kiện thực xảy Main clause If- clause Simple present Simple future (shall / will + verb) Example: - If the rain stops, we shall go for a walk - He will come if you call him Conditional sentence Type 2:Present Unreal Conditional ( Điều kiện khơng có thật tại/ tương lai) Điều kiện khơng có thật dùng để đề cập đến tình tưởng tượng xảy Main clause If-clause Past Subjunctive could / would + verb (Quá khứ giả định) * Quá khứ giả định hình thức khứ đơn động từ, riêng động từ “tobe” có hình thức WERE cho tất ngơi * MIGHT/ SHOULD… dùng thay cho could/ would Example: If I were you, I wonldn’t She can’t speak Chinese If she coul speak Chinses, she would get the job 3 Conditional sentence Type 3: Past unreal conditional ( Điều kiện thật q khứ) Điều kiện khơng có thật khứ dùng để đề cập đến tình xảy khứ If-clause Main clause Could/ would have + past participle Past perfect Example: - If he had been at the party last night, he would have met her - If the driver had driven more carefully, he wouln’t have had the accident II MỘT SỐ BIẾN THỂ CỦA CÂU ĐIỀU KIỆN: Biến thể câu điều kiện loại Main clause If- clause Simple present - would like to/must/have to/should + V-inf ( thể gợi ý, khuyên răn, đề nghị yêu cầu nhấn mạnh hành động) - present simple (diễn tả hậu tất yếu điều kiện đặt theo quy luật thói quen) - future continuous/future perfect (có thể xảy tương lai nhấn mạnh trạng thái diễn ra/hoàn thành việc) - (do not) V-inf (câu mệnh lệnh (chủ ngữ ẩn mệnh đề chính) - present continuous (đang xảy tại) Simple future - present perfect (không thời gian điều kiện có thật mà nhấn mạnh tính hồn tất nó) - can/may/must/have to/should/be going to + V-inf (câu đề nghị, gợi ý, bày tỏ ý kiến mang tính lịch sự) Examples: - If you want to lose weight, you should some exercise - If you eat this poisonous fruit, you die at once - If we leave Hanoi for Hue today, we shall be staying in Hue tomorrow - If you are hungry, go to a restaurant - If he is working, I won't disturb him If you have finished your homework, I shall ask for your help If I can help you, I will Biến thể câu điều kiện loại Main clause If-clause Past Subjunctive (Quá khứ giả định) - past continuous - past simple (việc xảy ra) - would be + V-ing would/could + V-inf Examples: - If the goalkeeper didn't catch the ball, they lost - If I were on holiday with him, I would be touring Italy now - If we were studying English in London now, we could speak English much better If you had taken my advice, you would be a millionaire now Biến thể câu điều kiện loại Main clause If-clause Past perfect - past perfect continuous - could/ would+ present perfect continuous - would + V-inf ( now) ( điều kiện khứ kết qủa tại) would/could + present perfect Examples: - If you had left Hanoi for Haiphong last Saturday, you would have been swimming in Doson last Sunday - If you had taken the medicine yesterday, you would be better now - If it hadn't been raining the whole week, I would have finished the laundry III ĐẢO NGỮ VỚI CÂU ĐIỀU KIỆN Đảo ngữ với câu điều kiện loại - Câu điều kiện loại có sử dụng “ should” thay khơng xác định khả xáy tương lai Đảo “should” lên đầu câu thay “If” - Nếu câu khơng có should mượn should đặt lên đầu câu thay cho if Điều kiện loại có sử dụng thời hoàn thành, lấy “should” thay “If” để ngun thể hồn thành với “have done” tất Main clause - If- clause Should + S + V-inf Should + S + V-P2 Examples: - If it should rain tonight, I will stay at home => Should it rain tonight, - If it rains, I will stay at home =>Should it rain, ……………… Simple future (shall / will + verb) - If she has finished the work, she can go home => Should she have finished the work, Đảo ngữ với câu điều kiện loại - Mệnh đề điều kiện loại có dùng động từ “tobe” số nhiều “were” dùng “were” thay”if” - Trong mẫu câu điều kiện loại đặc biệt có dùng “If” đầu câu: If it weren’t for + N ( .) => tách “were” khỏi “not’’sau đảo lên đầu câu thay “ If” Main clause - If-clause Were + S Were it not for could / would + verb Examples: - If I were you, i would love him => Were I you, - If it weren’t for your progress, i wouldn’t be here => Were it not for your progress, Đảo ngữ với câu điều kiện loại - Dùng “Had” đảo lên đầu câu thay “If” - Câu điều kiện loại đặc biệt với đại từ “it” đầu câu: If it hadn’t been for + N (Nếu khơng phải .) => Tách “had” khỏi “not” đảo lên đầu câu thay “If” - If-clause Had + S + V-p2 Had it not been for Main clause Could/ would have + past participle Examples: - If she had worked harder last year, she wouldn’t have failed the exam => Had she worked harder last year, - If it hadn’t been for hot weather, we would have had a wonderful holiday => Had it not been for hot weather, IV ĐIỀU KIỆN HIỂU NGẦM - Khi viết câu điều kiện, việc dùng “If”, ta sử dụng số từ thể điều kiện như: + suppose/ supposing (giả sử như) + on condition that ( với điều kiện là) + provided that/ as long as/ so long as ( miễn là) + in case ( trường hợp) + or/ or else ( là) + but for/ without/ otherwise ( không) + unless (trừ phi) B CÁC DẠNG BÀI TẬP ĐẶC TRƯNG- PHƯƠNG PHÁP GIẢI I DẠNG 1: Chọn động từ để hoàn thành mệnh đề mệnh đề câu điều kiện * Phương pháp giải - Nếu câu điều kiện cho trước mệnh đề, cần xét xem động từ mệnh đề cho sẵn thuộc loại nào, xem câu thuộc điều kiện loại mấy, dạng hay biến thể Như vậy, ta chọn động từ để hồn thiện mệnh đề cịn lại - Nếu câu điều kiện yêu câu ta chọn động từ để hồn thành mệnh đề ta phải xét ý nghĩa câu xem có manh mối trước khơng để xác định loại câu điều kiện, chọn động từ để hoàn thành câu cho thích hợp - Nếu câu điều kiện có sử dụng q khứ hồn thành mệnh đề điều kiện mệnh đè có từ “now” loại câu điều kiện pha trộn * Ví dụ cụ thể If you have a map along, you _ get lost a will b will not c wouldn’t d would - Xét thấy động từ mệnh đề điều kiện “have”- chia đơn, câu điều kiện loại Vậy động từ mệnh đề tương lai đơn, ta giới hạn đáp án “a, b” Thêm nữa, xát ý nghĩa thì” b” đáp án thích hợp If I lived by the sea, I _ a lot of swimming a would b will c d did - Tương tự trên, câu điều kiện loại Vậy đáp án thích hợp “a” Water freezes if the temperature _ below zero a fall b will fall c falls d fell - Nhận thấy, mệnh đề câu dùng với hình thức câu mệnh lệnh Vậy biến thể câu điều kiện loại 1, mệnh đê điều kiện chia đơn Đáp án “c” What _ you if you _ a King? a will/are b would/were c would have/had been d would/had been - Đọc câu, ta thấy giả định khơng có thật tại, bạn khơng phải vua ( King) Vậy la điều kiện loại Đáp án “b” II DẠNG 2: Tìm từ cụm từ cần phải sửa lại * Phương pháp giải -Dựa vào hình thức loại câu điều kiện để xác định xem câu thuộc điều kiện loại xem xét tương xứng động từ mệnh đề câu để xác định lỗi sai - Dựa vào từ điều kiện xem câu dùng “unless” hay “if” để xác định mệnh đề theo sau từ điều kiện này, tìm lỗi sai * Ví dụ cụ thể If a drop of oil is placed in a glass of water, it would float to the top A B C D -Động từ mệnh đề điều kiện dùng với thể bị động đơn, lỗi sai thuộc phần động từ mệnh đề chính.Vậy lỗi sai “C” How nice it would be for our parents if we could built the house A B C D - Xét thấy dạng biến thể điêu kiện loại 2, mệnh đề điều kiện dùng “could” Tuy nhiên, động từ sử dụng sau “could” phải dạng nguyên thể, lỗi sai “D” Unless she doesn’t come, I will miss her A C D Đây hình thức câu điều kiện loại 1, sử dụng “unless” mệnh đề liền sau “unless” không chia phủ định, lỗi sai “A” III DẠNG 3: Viết lại câu, chọn câu chuyển đổi tình thành câu điều kiện, hoăc sử dụng cụm từ mang ý nghĩa điều kiện khác để viết lại câu cho nghĩa không đổi, chọn câu tương đương nghĩa * Phương pháp giải - Nếu tình đưa mà có khả xảy viết lại với câu điều kiện loại - Nếu tình đưa khơng có khả xảy viết lại với câu điều kiện loại động từ mệnh đề điều kiện phải trái ngược với tình khơng có thật khơng thể xảy - Nếu tình đưa khứ, diễn tả việc khơng xảy viết lại với câu điều kiện loại động từ mệnh đề điều kiện phải trái ngược với tình khơng có thật khơng thể xảy - Cịn với trường hợp viết lại câu, chọn câu sử dụng cụm từ mang ý nghĩa điều kiện khác áp dụng số cơng thức sau: + Unless = If………not + If + clause = Without But for +N (biến đổi động từ mệnh đề sau If thành danh từ) If it weren’t for ( Đk loại 2) If it hadn’t been for ( Đk loại 3) + Vinf + or/ otherwise + clause = If + S + not V, clause + Suppose/ supposing ….= what if ? * Ví dụ cụ thể 1- I didn’t have an umbrella with me so I got wet If …………………………… - Tình khơng xảy khứ, viết lại với câu điều kiện loại Đáp án: If I had had an umbrella with me, I wouldn’t have got wet 2- I’ll call the police if you don’t leave me alone Unless……………………………… - Câu biến đổi mệnh đề sau if thành mệnh đề sau unless Đáp an: Unless you leave alone, I’ll call the police 3- Without Jack’s help, I wouldn’t have been able to move this table If………………… - Câu dùng If thay cho Without, biến đổi danh từ sau Without thành động từ sau If Đáp án: If Jack hadn’t helped me, I wouldn’t have been able to move this table 4- If you see Peter, tell him he should be here at 00 Should………………………… - Câu chuyển đổi từ hình thức sang đảo ngữ Đáp án: Should you see Peter, tell him he should be here at 00 C CÁC BÀI TẬP TỰ LUYỆN I Put the verbs in brackets into the correct tenses * Type 1 If Liz studies hard, she ………………… (pass) her test If I have time tomorrow, I ……………….(go) shopping with you If you …………………(turn) off the light, we will be in the dark If I see Duc, I ………………………(give) him your message He …………….(send) you some information if you tell him your address If Kate ……………(be) late again, she will lose her job She will be sick if she ………………….(eat) all that ice-cream If we ……….(go) out tomorrow evening, we (miss) that new programme on TV I (be) angry if it turns out that you are wrong 10 If he (finish) with the computer, I will put it away * Type If I had a typewriter I ………(type) it myself If I ……… (know) his address I’d give it to you He ……….(look) a lot better if he shaved more often If you ………(play) for lower stakes you wouldn’t lose so much If he worked more slowly he ………(not make) so many mistakes I shouldn’t drink that wine if I ……………(be) you More tourist would come to this country if it ………… (have) a better climate If I were sent to prison you …………(visit) me? If someone……… (give) you a helicopter what would you with it? 10 I ………….(buy) shares in that company if I had some money * Type If I had known that you were in hospital I (visit) you The ground was very soft But for that, my horse (win) If you (arrive) ten minutes earlier you would have got a seat You would have seen my garden at its best if you (be) .here last week But for his quickness I (be) killed I shouldn’t have believed it if I (not see) it with my own eyes If he had slipped he (fall) 500 meters If he had asked you, you (accept) ? If I (have) a map I would have been all right 10 If I (know) that you were coming I’d have baked a cake *KEYS: * Type 1 will pass is will go eats turn go- will miss will give will be will send 10 finishes * Type would type were knew had would look would- visit 4.played gave would not make 10 would buuy * Type would have visited hadn’t seen could have won would have fell had arrived would – have accepted had been had had would have been 10 had known II Choose the best answer among A, B, C or D to complete each sentence I would have visited you before if there _ quite a lot of people in your house A hadn't B hadn't been C wouldn't be D wasn't If you had caught the bus, you _ late for work A wouldn't have been B would have been C wouldn’t be D would be If I _, I would express my feelings A were asked B would ask C had been asked D asked Will you be angry if I _ your pocket dictionary? A stole B have stolen C were to steal D steal You made a mistake by telling her a lie It _ better if you _ to her A would have been / hadn't lied B would be / didn't lie C will be / don't lie D would be / hadn't lied John would be taking a great risk if he _ his money in that business A would invest B invested C had invested D invests If I _ her phone number, I _ her last night A had known / could have phoned B knew / would have phoned C know / can phone D knew / could phone If he the truth, the police wouldn’t arrest him A tells B told C had told D would tell If you press that button what _? A would happen B would have happened C will happen D happen 10 She says if she _ that the traffic lights were red she _ A had realized / would stop B realized / could have stopped C has realized / stopped D had realized / would have stopped 11 I am very thin I think, if I _ smoking, I might get fat A stop B had stopped C will stop D stopped 12 If I _ that yesterday, I _ them A had discovered / would inform B had discovered / would have informed C had discovered / could inform D discovered / can inform 13 If you _ to the course regularly, they a certificate last year A go / gave B go / give C had gone / would have given D went / would give 14 I think he is not at home If he _ in, he the phone A was / answered B were / would answer C were / would have answered D.had been / would have answered 15 If I in London now, I could visit British Museum A were B had been C have been D would be 16 If Columbus _ money from Queen Isabella, he _ across the Atlantic A not receive / could not sail B had not received / might not have sailed C did not receive / might not have sailed D would not receive / might not sail 17 If you didn't wear shabby clothes, you _ more good-looking A will be B would be C would have been D can be 18 If your hair _ grey now, what you ? A went / would /do B goes / would /do C had gone / would/do D had gone / would have / done 19 If you be someone, who you ? A could / would / have been B could / would / be C can / will /be D are able to / will / be 20 If I an Angel, I would try to make happy all the children A am B have been C were D had been 21 Would she go if she _? A were invited B was be invited C have been invited D be invited 22 The room if it is not empty A couldn’t be repainted B cannot be repainted C could be repainted D can be repainted 23 If I were a better conversationalist, _ to parties more often? A I would be invited B I would have been invited C would I be invited D would I have been invited 24 I would never have believed it with my own eyes A if I didn’t see B if I hadn’t seen C if I haven’t seen D if I wouldn’t have seen 25 Carol was late for work this morning But for the traffic jam, she half an hour earlier A could come B could have come C had come D can have come 26 Don’t worry home late tonight A when I’ll be B if I’ll be C unless I’ll be D if I’m 27 If I the flu, I would have joined you for the trip A hadn’t had B haven’t had C didn’t have D has had 28 But for the hold-up, we here in time A would have been B could be C had been D must have been 29 I lost your phone number Otherwise, I you much earlier A will contact B would have contacted C would contact D had contacted 30 If the lecturer so quickly, we’d have understood his speech A didn’t speak B hadn’t spoken C wouldn’t have spoken D shouldn’t have spoken 31 If you put salt in water, it A dissolves B would dissolve C could dissolve D dissolved 32 , please paint the windows before you leave A If you’ll have enough time B If you have enough time C Unless you have enough time D Unless you can have enough time 33 Jeff wouldn’t have bumped into the waitress if he in such a hurry A weren’t B hasn’t been C hadn’t been D wouldn’t have been 34 If you Mary by chance, please give her my phone number A met B should meet C could meet D will meet 35 My parents lent me the money Otherwise, I this shop A hadn’t opened B couldn’t open C weren’t be able to open D wouldn’t have opened 36 I think she would forgive you if you to speak to her A are trying B would try C tried D have tried 37 I wouldn’t have to take this course if my English better A were B had been C would be D would have been 38 If we hadn’t got lost, we arrived much earlier A had B would be C might be D could have 39 But for his wife’s encouragement, he gotten to the top of his profession A hadn’t B hasn’t C won’t have D wouldn’t have 40 “I’m too tired to study.” “If you hadn’t watched that late movie last night, you _ so tired now.” A wouldn’t be B hadn’t been C wouldn’t have been D would have been 41 If it hadn’t been for the life-jackets, most passengers _ drowned in that accident A would have been B would be C had been D were 42 Slow down _ A In case you will get and accident B Provided that you would get and accident C And you will get and accident D Or you will get an accident *KEYS: B A A D A B A B C 10 11 12 13 D D B C 15 16 17 18 19 20 21 22 23 24 25 26 27 A B B A B C A B C B B B A 29 30 31 32 33 34 35 36 37 38 39 40 41 B B A B C B D C A D D A A III One of the four underlined parts marked A, B, C, D in each sentence is not correct in standard English Identify them If Lucia had been here now, she would find out the truth about her uncle’s accident A B C D If a student takes a course on Computer Science, it will take him four years doing the course A B C D Unless it did not rain, Peter would pay us a visit A B C D If had I known you were in financial difficulty, I would have helped you A B C D If I had knew the time when the match started, I would have told you A B C D If she had finished the work, she can go home A B C D If I had spoken more confident at the interview, they would have offered me the job A B C D If we had had a map, we would not be lost yesterday A B C D Had I known Alice’s address, I would write to her A B C D 10 If I had realized that the traffic lights were red, I would stop A B C D 11 If had you sent the application form to that company, you would have been offered a job A B C D 12 If you don’t care conservation the environment, we will get unavoidable disasters A B C D 13 He spends money carelessly as if he was a millionaire A B C D 14 Unless you work harder, you will be sack because of your laziness A B C D 15 Unless there had been the heavy storm, the climbers will not have died A B C D 16 She has found that nobody can help her if she did not try her best to it herself A B C D *KEYS: A D A A B A C C C 10 D 11 A 12 B 13 D 14 C 15 D 16 B 14 B 28 B 42 D IV Choose the best option “I couldn’t have made it without your help” means A I couldn’t have made it if you helped me B I couldn’t have made it if you had helped me C I couldn’t have made it if you hadn’t helped me D I couldn’t have made it if you didn’t help me She didn’t stop her car because she didn’t see the signal A If she saw the signal, she would stop her car B If she had seen the signal, she would stop her car C If she had seen the signal, she would have stopped her car D If she saw the signal, she would have stopped her car His flight was delayed so he couldn’t be here on time A He would be here in time if his flight were not delayed B He would have been here in time if his flight hadn’t been delayed C He would be here in time if his flight hadn’t been delayed D He would have been here in time if his flight weren’t delayed Without your help, I couldn’t overcome the problem A If you don’t help me, I can’t overcome the problem B If you didn’t help me, I couldn’t overcome the problem C If you hadn’t helped me, I couldn’t overcome the problem D If you hadn’t helped me, I couldn’t have overcome the problem Thanks to Laura’s report, I was able to finish the project A If there isn’t Laura’s report, I wouldn’t finish the project B Had it not been for Laura’s report, I wouldn’t have been able to finish the project C If Laura didn’t help me, I wouldn’t finish the project D I wouldn’t have finished the project if Laura didn’t help me I think you should stop smoking A If I am you, I will stop smoking B If I were you, I will stop smoking C If I were you, I would stop smoking D If I had been you, I would stop smoking If / you / want / get ahead / this company / have / be prepared / work / long hours A If you want to get ahead this company, you have to be prepared work long hours B If you want to get ahead in this company, you have to be prepared working long hours C If you want to get ahead for this company, you have to be prepared working long hours D If you want to get ahead in this company, you have to be prepared to work long hours not / forget / keep / touch / me / if / you / come / Singapore A Don’t forget keeping in touch with me if you come to Singapore B Don’t forget to keeping in touch with me if you come to Singapore C Don’t forget to keep in touch with me if you come to Singapore D Don’t forget kept in touch with me if you come to Singapore If I can’t afford something, I never buy it A I never buy anything that I can’t afford B I never buy something that I can’t afford C I never buy anything that I can afford D The thing that I can’t afford I never buy anything 10 The police want to contact with people if they saw him A The police want to talk to anyone who sees the man B The police want to talk to anyone who saw the man C The police wants to talk to anyone who saw the man D The police who saw the man want to talk to someone 11 How should people be punished if they start a fire? A What we should with someone whom starts the fire? B What should we with someone starts the fire? C What with someone who starts the fire should we do? D What should we with someone who starts the fire? 12 The wind was so strong that the cottage collapsed A The wind was too strong to collapse the cottage B If the wind were not so strong, the cottage would not collapse C Due to the strong wind, the cottage collapsed D It is the strong wind made the cottage collapsed 13 I regret behaving so impolitely with her and she was disappointed A Unless I behave so impolitely with her, she would not be disappointed B Provided that I did not behave so impolitely with her, she would not be disappointed C I wish I did not behave so impolitely with her D If I had not behaved so impolitely with her, she would not have been disappointed 14 If I had been more confident, I would have passed the driving test A I failed my driving test because of my lack of confidence B I had failed my driving test because of my lack of confidence C I passed the driving test in spite of my lack of confidence D I passed the driving test with confidence 15 If I had time, I would go with you A.I am free and surely go with you B.I am too busy to go with you C I will go with you because I have time D I am free enough to go with you *KEYS: C A B 10 B B 11 D C 12 C B 13 D C 14 A V Rewrite the sentences using conditional sentences His father often punishes him because he is lazy She is too old so she cannot go hiking The car is very expensive and he doesn’t have enough money to buy it They don’t go for a picnic because the weather is bad I shan’t buy a dictionary; I don’t have enoughmoney Go right now or you’ll be late for the train It rained heavily; that’s why I can’t go to school You got into so much trouble because you didn’t listen to me I am sick That's why I can’t help you now 10 She came, so he wasn’t disappointed 11 Without a visa, she couldn’t have come to that country 12 It rained last night so I didn’t go to the barbecue 13 Hurry up, or we will be late for the exam 14 She doesn’t pay attention to her cooking so the food is horrible 15 Without the sun, man would live in the darkness *SUGGESTED ANSWERS: If he weren’t lazy, his father would not punish him often If she weren’t too old, she could go hiking If the car were cheap, he would buy it I the weatherwere good, they would go for a picnic If I had enough money, I would buy a dictionary If you don’t go right now, you’ll be late for the train If it hadn’t rained heavily, I could have gone to school If you had listened to me, You wouldn’t have got into so much trouble If I weren’t sick, I could help you now 10 If she hadn’t come, he would have been disappointed 11 If she hadn’t had a visa, she couldn’t have come to that country 12 It hadn’t rained last night, I could have gone to the barbecue A 15 B C 13 If we don’t hurry up, we will be late for the exam 14 If she paid attention to her cooking, the food wouldn’t be horrible 15 If there weren’t the sun, man would live in the darkness  ... hoàn thành mệnh đề mệnh đề câu điều kiện * Phương pháp giải - Nếu câu điều kiện cho trước mệnh đề, cần xét xem động từ mệnh đề cho sẵn thuộc loại nào, xem câu thuộc điều kiện loại mấy, dạng hay... your progress, Đảo ngữ với câu điều kiện loại - Dùng “Had” đảo lên đầu câu thay “If” - Câu điều kiện loại đặc biệt với đại từ “it” đầu câu: If it hadn’t been for + N (Nếu khơng phải .) => Tách... ĐẢO NGỮ VỚI CÂU ĐIỀU KIỆN Đảo ngữ với câu điều kiện loại - Câu điều kiện loại có sử dụng “ should” thay khơng xác định khả xáy tương lai Đảo “should” lên đầu câu thay “If” - Nếu câu khơng có