If用法汇总及练习.doc

If 用法汇总1、主将从现 （主句为一般将来时,从句为一般现在时）；eg:If it rains(从句) ,I will stay at home（主句）.=I will stay at home if it rains.2、主句含有情态动词 （must、may、can etc.）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 fast3、主句为祈使句,从句要用一般现在时态；eg:Dont play computer games if you dont finish your homework.4、 是否=whetherAsk if he is at home. I wonder if she is ill.5、 虚拟语气 eg:If I were a bird ,I would fly in the sky.（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后.a.同现在事实相反的假设从句用一般过去时 should( would) +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从句用过去完成时 should(would) have+ 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.表示对将来的假想一般过去时 ，were+ to do， 从句：主+ should/would/could/might+v原形should+ v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 sentB. had known, would have sentC. know, would send D. knew, would have sent2. Mary is ill today. If she _, she _ absent from school.A. were not ill; wouldnt be B. had been ill; wouldnt have beenC. had been ill; should have been D. hadnt been ill; could be3. He acted as if he _ everything in the world.A. knew B. knows C. has known D. wont know4. If you had enough money, what _?A. will you buy B. would you buyC. would you have boughtD. will you have bought5. If Mr. Young _ with justice, he _ such a wrong thing.A. were treated; wouldnt doB. had been treated; wouldnt have doneC. were treated; wouldnt have doneD. had been treated; wouldnt do6. What _ if there _ no light during the day?A. will happen; wasB. would happen; isC. happens; were D. would happen; were7. The spokesman acted that way as if he _ anything about the accident but actually he did.A. doesnt hear B. didnt hear C. havent heard D. hadnt heard8. 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; were9. Many Chinese movie stars now have given up their Chinese nationality. If I were them,I _ that.A. shouldnt do B. didnt do C. hadnt done D. wont do10. I want to get back by 5 oclock if _.A. likely B. can C. possible D. Probable11. It seems as if it _ already summer now but it is only February.A. is B. was C. were D. had been12. If Henry had not pulled his cap low over his brow, he _ by the police.A. might be recognized B. might have been recognizedC. would have recognized D. was to have been recognized13. There is a ring at the door. That _ be the postman, I suppose.A. will B. wouldC. is going toD. was going to14. Look at the dark cloudsthere _ be a storm.A. will B. must have beenC. is going toD. would15. Why are you taking the pictures down?I _ the wall.A. paint B. have just paintedC. am going to paint D. will have painted16. Can I stay at home tomorrow?Yes, you can if it_.A. will snow B. is going to snowC. snows D. snowed17. I dont know if he _ this afternoon. But if he _, I will tell you.A. will come; will do; B. comes; will doC. will come; does D. comes; does18. I thought I asked you to fix the radio.Oh, Im sorry. I _ it right away.A. am to do B. will doC. was about to doD. am going to do19. The WTO cant 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 though20. Ask him to ring me up if you _ him.A. see B. saw C. would see D. will see21. Its so late. I dont think he _ come.A. would B. should C. is going to D. shall22. If people _ polluting the air, animals and plants will die soon.A. dont stop B. didnt stopC. shall not stopD. havent stopped23. If you _ an interesting day out, _ the Science Museum.A. want; visiting B. want; visitC. want to; visit D. wanting; visit24. If the pure water is heated to 100 centigrade degrees, it _ boil.A. is going to B. will C. would D. is to25. Is a dictionary available, _ so, where?A. if B. if is C. and if D. and if is15 BAABB 610 DDCAC 1115 CBACC 1620 CCBCA 2125 CABBC最后一练1.If you _ to the party, youll have a great time. A. will go B. went C. go D. going2. 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. with5 I _ her the answer if she _me. A. can tell, will ask B. will tell, will ask C. would tell, ask D. will tell, asks6. What are you going to do tomorrow?-Well go to the library tomorrow if it _. A. isnt rain B. rain C. wont rain D. doesnt rain7.Do you know when he will come back tomorrow?-Sorry, I dont know. When he _ back, Ill tell you. A. comes B. will come C. come D. may come 8. What will you do if you _ to the old folks home visit?A. go B. went C.going D. will go9. If I eat _ food, Ill be very fat.A. too many B. many too C. too much D. much too10. Ill give the book to him if he _ here next Sunday.A. will come B. comes C. is coming D. came11. There _an English film in our school tomorrow.A. is going to have B. will have C. is going to be D. has12. Could you tell us where _？A. will the next Olympic Games held B. the next Olympic Games will be heldC. would the next Olympic Games be held D. the next Olympic Games would be held13. When my mother returned last night, I _ a book. A. read B. am reading C. was reading D. am going to read14.What _ you _ when it began to rain?A. do, do B. were, doing C. are, doing D. did, do15. Ill wake you up when he _back.A. will B. is going to come C. comes D. come1-5 CDBAD 6-10 DAACB 11-15 CBCBC