If-用法匯總及練習.doc

If 用法匯總1、主將從現 （主句為一般將來時,從句為一般現在時）；eg:If it rains(從句) ,I will stay at home（主句）.=I will stay at home if it rains.2、主句含有情態(tài)動詞 （must、may、can etc.）從句為一般現在時；eg:If you drive too fast ,you may have an accident.=You may have an accident if you drive too fast3、主句為祈使句,從句要用一般現在時態(tài)；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、 虛擬語氣 eg:If I were a bird ,I would fly in the sky.（事實我不可能是鳥）時態(tài)：可以表示過去，現在和將來的情況，它的基本特點是時態(tài)退后.a.同現在事實相反的假設從句用一般過去時 should( would) +動詞原形If they were here,they would help you.b.表示于過去事實相反的假設從句用過去完成時 should(would) have+ 過去分詞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.表示對將來的假想一般過去時 ，were+ to do， 從句：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.單項練習（每個必須讓學生翻譯）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最后一練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 re