一、时态 如果主句是一般将来时态，这时从句不可以用将来时态，而要用一般现在时。 例如： I won’t go there with you if it rains tomorrow. 如果明天下雨的话，我就不和你一起去那儿了。 二、主从句的位置 大多数情况下，从句可以位于主句之前，也可以位于主句之后。不过从句在 前时，主从句之间必须用逗号隔开。例如： Please tell me if he comes back. = If he comes back, please tell me. 如果他回来了，请告诉我一声。 三、 if 的两面性 if 引导条件状语从句时意为 “ 如果 ” ，如果引导宾语从句则意为 “ 是否 ” 。请比较： 1) We will go out if it is fine tomorrow. 2) I don’t know if the train has arrived. 句 1) 中 if 引导的是状语从句。这个从句表示 “ 条件 ” ，整个句子的意思是 “ 如果 明天天气好，我们就出去 ” 。句 2) 中 if 引导的是宾语从句，充当谓语动词 don’t know 的宾语，整个句子的意思是 “ 我不知道火车是否到了 ” 。

1.If it ______ sunny tomorrow, I ____ boating. A. is go B. will be, go C. is, will go D. will be, will go What will you do if it ______ tomorrow, ----I’ll stay at home and watch TV. A. rain B. rains C. will rain D. is raining 1.Run fast, or you’ll be late for school. _____ you _____ ______ fast, you’ll be late for school. 2. You can buy the dictionary if you take enough money with you. Take enough money with you, ______ _____ ______ buy the dictionary. 3. If there is no air, none of us can live. None of us can live _______ _________. Ifdon’trun and you can without air

if 条件状语从句的时态练习 1. Diana (will go/go/goes) to Europe if she (will pass/pass/passes) the exams. 2. The graduates (will teach/teach/teaches) in the poor village if the teacher (will agree/ agree/agrees) soon. 3. If there (will be/ are/is) a car accident, they (will call/call/calls) 110 for help at once. 4. If it (won’t/don’t/doesn’t/ isn’t) rainy, we (will take/ take/takes) walk outside. 5. If a UFO (will land/land/lands) in front of me, I (will go/go/goes) in to look for the alien. will go passes will teach agrees will go lands will takeisn’t will call is

6. If he (will have/have/has) money, he (will build/build/builds) a science lab. 7. Don’t wait for me if I (am/ will be) late. 8. They (won’t/don’t) go to the beach if it (will rain/rain /rains). 9. I (will call/ call) you if he (will stay/stay /stays) at home. 10. Mr. Smith (will let/ let/lets) you know if he (will need/ need/ needs) help. 11. (Will / Do/ Does) he visit the museum if he (won’t / don’t/ doesn’t) get tired? 12. Where (will/ do/does) they live if they (will miss/ miss/ misses) the bus? rains misses will doesn’t Will needswill let stayswill call won’t am will build has

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. When my mother returned last night, I ____ a book. A.read B. am reading C. was reading D. am going to read 14.What ____ you ____ when it began to rain? A. do, do B. were, doing C. are, doing D. did, do 15. I’ll wake you up when he ____back. A. will B. is going to come C. comes D. come

1. If you ________ (feel) tired, you _______________ (have) to have a rest. 2. Where _______ he _________ (see) the film if he ________________(have) time? 3. If there __________(be) fewer trees, there _______________( be) more pollution. 4. He _____________(dress) more casually if he ________________( not work) on weekends. 5. If Marcia _____________(live) alone, she ___________________( keep) a pet parrot. 6. Lana ________________( buy) a new dress if the old one ____________(be) out of style. feel can have can see has are will be will dress doesn’t work lives should/will keep can/will buy is