If-用法汇总及练习

If 用法汇总用法汇总 1 主将从现 主将从现 主句为一般将来时 主句为一般将来时 从句为一般现在时 从句为一般现在时 eg If it rains 从句从句 I will stay at home 主句 主句 I will stay at home if it rains 2 主句含有情态动词 主句含有情态动词 must may can etc 从句为一般现在时 从句为一般现在时 eg If you drive too fast you may have an accident You may have an accident if you drive too fast 3 主句为祈使句 主句为祈使句 从句要用一般现在时态 从句要用一般现在时态 eg Don t play computer games if you don t finish your homework 4 是否是否 whether Ask if he is at home I wonder if she is ill 5 虚拟语气虚拟语气 eg If I were a bird I would fly in the sky 事实我不可能是鸟 事实我不可能是鸟 时态 可以表示过去 现在和将来的情况 它的基本特点是时态退时态 可以表示过去 现在和将来的情况 它的基本特点是时态退 后后 a 同现在事实相反的假设同现在事实相反的假设 从句用一般过去时从句用一般过去时 should would 动词原形动词原形 If they were here they would help you b 表示于过去事实相反的假设表示于过去事实相反的假设 从句用过去完成时从句用过去完成时 should would have 过去分词过去分词 If she had worked harder she would have succeeded If my lawyer had been here last Saturday he would have prevented me from going c 表示对将来的假想表示对将来的假想 一般过去时一般过去时 were to do 从句 主从句 主 should would could might v 原形原形 should v 原形 原形 If you succeeded everything would be all right If you were to succeed everything would be all right If you should succeed everything would be all right 单项练习 每个必须让学生翻译 1 If I where he lived I a note to him A know would have sent B had known would have sent C know would send D knew would have sent 2 Mary is ill today If she she absent from school A were not ill wouldn t be B had been ill wouldn t have been C had been ill should have been D hadn t been ill could be 3 He acted as if he everything in the world A knew B knows C has known D won t know 4 If you had enough money what A will you buy B would you buy C would you have bought D will you have bought 5 If Mr Young with justice he such a wrong thing A were treated wouldn t do B had been treated wouldn t have done C were treated wouldn t have done D had been treated wouldn t do 6 What if there no light during the day A will happen was B would happen is C happens were D would happen were 7 The spokesman acted that way as if he anything about the accident but actually he did A doesn t hear B didn t hear C haven t heard D hadn t heard 8 If it not for the fact that you ill now I would surely punish you A is are B were were C were are D was were 9 Many Chinese movie stars now have given up their Chinese nationality If I were them I that A shouldn t do B didn t do C hadn t done D won t do 10 I want to get back by 5 o clock if A likely B can C possible D Probable 11 It seems as if it already summer now but it is only February A is B was C were D had been 12 If Henry had not pulled his cap low over his brow he by the police A might be recognized B might have been recognized C would have recognized D was to have been recognized 13 There is a ring at the door That be the postman I suppose A will B would C is going to D was going to 14 Look at the dark clouds there be a storm A will B must have been C is going to D would 15 Why are you taking the pictures down I the wall A paint B have just painted C am going to paint D will have painted 16 Can I stay at home tomorrow Yes you can if it A will snow B is going to snow C snows D snowed 17 I don t know if he this afternoon But if he I will tell you A will come will do B comes will do C will come does D comes does 18 I thought I asked you to fix the radio Oh I m sorry I it right away A am to do B will do C was about to do D am going to do 19 The WTO can t live up to its name it does not include a country that is home to one fifth of mankind A as long as B whether C if D even though 20 Ask him to ring me up if you him A see B saw C would see D will see 21 It s so late I don t think he come A would B should C is going to D shall 22 If people polluting the air animals and plants will die soon A don t stop B didn t stop C shall not stop D haven t stopped 23 If you an interesting day out the Science Museum A want visiting B want visit C want to visit D wanting visit 24 If the pure water is heated to 100 centigrade degrees it boil A is going to B will C would D is to 25 Is a dictionary available so where A if B if is C and if D and if is 1 5 BAABB 6 10 DDCAC 11 15 CBACC 16 20 CCBCA 21 25 CABBC 最后一练 1 If you to the party you ll have a great time A will go B went C go D going 2 It will be a long time Peter his work A since has finished B after finishes C when will finish D before finishes 3 What will father us from Japan A take B bring C carry D make 4 Weifang is famous kites A for B to C on D with 5 I her the answer if she me A can tell will ask B will tell will ask C would tell ask D will tell asks 6 What are you going to do tomorrow We ll go to the library tomorrow if it A isn t rain B rain C won t rain D doesn t rain 7 Do you know when he will come back tomorrow Sorry I don t know When he back I ll tell you A comes B will come C come D may come 8 What will you do if you to the old folk s home visit A go B went C going D will go 9 If I eat food I ll be very fat A too many B many too C too much D much too 10 I ll give the book to him if he here next Sunday A will come B comes C is coming D came 11 There an English film in our school tomorrow A is going to have B will have C is going to be D has 12 Could you tell us where A will the next Olympic Games held B the next Olympic Games will be held C would the next Olympic Games be held D the next Olympic Games would be held 13