英國前首相撒切爾夫人(Margaret Thatcher)曾用if條件句對男人和女人進行評價: In politics, if you want someone to make a speech, ask a man; if you want something done, ask a woman. 在政治領域,如果你想要有人發(fā)表演說,那就找男士去;而如果你想真正把事情解決,那就找女士。 一、概念 連詞if的意思是“如果”,它引導的句子表示某事發(fā)生所需要的條件,即“在……條件下某事才能發(fā)生”,在句子中充當狀語,因此我們稱之為條件狀語從句。在復合句中連詞if引導的句子為從句,被修飾的句子為主句。從句可以放在主句后,也可以放在主句前,從句放在主句前時,應用逗號將它與主句隔開。例如: We’ll go to the Great Wall if it doesn’t rain tomorrow. = If it doesn’t rain tomorrow, we’ll go to the Great Wall. 如果明天不下雨,我們就去長城。 二、用法 1. 條件狀語從句通常由連詞if引導,意為“如果,假如”,主句不能用be going to 表示將來,而應該用shall或will。例如: If I’m free tomorrow, I’ll go with you. 如果我明天有空,我將會和你一起去。 2. if引導的條件狀語從句,主句用一般將來時,從句則用一般現(xiàn)在時,即“主將從現(xiàn)”。例如: If it is sunny tomorrow, I’ll climb the hill. 如果明天天氣晴朗,我將去爬山。 3. 正確區(qū)分if引導的條件狀語從句和if引導的賓語從句。 在條件狀語從句中,if表示“如果”;而在賓語從句中,if表示“是否”??梢杂孟旅娴姆椒▍^(qū)分: 1) 從句前置法:if引導的條件狀語從句,可以放在主句之前并用逗號隔開,也可放在主句之后;而if引導的賓語從句只能放在主句之后。因此如果把if放在主句之前,句子通順,意義不變,則是條件從句,否則是賓語從句。例如: He will help you if you ask him. = If you ask him, he will help you. 如果你問他,他會幫助你。 2) whether替換法:if引導賓語從句時,其意為“是否”,通??捎脀hether替換,意義不變,而if引導條件狀語從句時不能用whether替換。因此,可用whether替換的是賓語從句,不能替換的是條件從句。例如: I want to know if you will go tomorrow. = I want to know whether you will go tomorrow. 我想知道你明天是否去。 注意:區(qū)分if的用法有著極為重要的意義,因為在條件狀語從句中,主句用將來時,從句用一般現(xiàn)在時;而在賓語從句中,當主句是一般現(xiàn)在時,從句可用所需的任何時態(tài),主句是一般過去時,從句用過去的某種時態(tài)。 一、單項選擇 1. If you _____ to the party, you’ll have a great time. A. will go B. went C. go D. going 2. 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 3. — 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 4. — 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 5. I’ll give the book to him if he ____________ here next Sunday. A. will come B. comes C. is coming D. came 6. There ____________ an English film in our school tomorrow. A. is going to have B. will have C. is going to be D. has 7. I’ll wake you up when he ____________back. A. will B. is going to come C. comes D. come B. rains C. rained D. is rained A. is going to have B. will be C. is going to play D. will play B.is raining C.rains D.will rain 二、用所給詞的適當形式填空 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. 7. The twins ________ (fight) if they________ (argue). 8. I ________ (have) a bake sale if I ________ (need) money for education. 9. Peter ________ (send) me a beautiful souvenir if he ________ (go) to Spain. 10. If Mr. Green ________ (say) I am hard- working, my parents ________ (feel) glad. 11. I ________ (go) to the beach if it ________ (not rain) this week. 12. ________they ________ (have) a match if the P.E. teacher________ (be) not busy? 13. He ________ (write) a letter to his grandparents if he ________ (get) his report card this week. 14. If she ________ (get) up late, she ________ (not catch) the early bus. 15. Peter ________ (major) in English if he ________ (pass) the exams in Peking University. 三、完成句子 1.如果他遲到了,會發(fā)生什么事情? What _______ ________ if he _______ late? 2. 如果努力學習,你就會取得好成績。 If you_______ _______, you _______ _______ good _______. 3. 他如果看電視太久了,他的父母會不高興。 If he _______ TV too much, his parents _______ _______ unhappy. 4. 如果我們?yōu)樗e辦生日聚會,大家都會來的。 Everyone _______ _______ if we _______a birthday party _______ him. 5. 如果明天不下雨,我會和你一起去公園的。 If it _______ _______ tomorrow, I _______ go to the park _______ you. 6. 如果她睡過頭了,就會誤了開會的。 She _______ _______ _______ _______ the meeting if she _______ _______. 7. 如果他有空,他會幫助你的。 If he _______ _______, he _______ _______ you. 8. 如果Tom考試不及格,他就沒有機會上高中了。 Tom _______ miss the chance to go to the high school if he _______ the exams. 9. 你如果抄同學的作業(yè)就不能學好各門功課。 You _______ _______ good at all the subjects if you _______ the other students’ homework. 參考答案 一、單項選擇。 1. C。本題是if引導的條件狀語從句,主句用一般將來時,從句用一般現(xiàn)在時,即“主將從現(xiàn)”,所以答案為C。 2. D。根據(jù)句意“如果她問我,我就告訴她答案。”可知本句是if引導的條件狀語從句,主句用一般將來時,從句用一般現(xiàn)在時,從句的主語為單三,動詞后加-s,所以答案為D。 3. D。條件狀語從句,主句用一般將來時,從句用一般現(xiàn)在時,rain在此是實義動詞“下雨”的意思,故答案為D。 4. A。根據(jù)“主將從現(xiàn)”可知本句答案為A。此題是when引導的時間狀語從句。 5. B。根據(jù)“主將從現(xiàn)”可知答案為B。 6. C。be going to do,will do都可以表示將來的動作,但只有選項C符合There be句型要求。 8. B。根據(jù)“主將從現(xiàn)”可知答案為B。 9. B。本題考查there be句型的一般將來時,there will be,故答案為B。 10. C。根據(jù)“主將從現(xiàn)”可知答案為C。 二、用所給詞的適當形式填空 1. feel; will have 2. will; see; has 3. are; will be 4. will dress; doesn’t work 5. lives; will keep 6. will buy; is 7. will fight; argue 8. will have; need 9. will send; goes 10. says; will feel 11. will go; doesn’t rain 12. Will; have; is 13. will write; gets 14. gets; won’t catch 15. will major; passes 三、完成句子 1. will happen; is 2. study hard; will get; grades 3. watches; will be 4. will come; have; for 5. doesn’t rain; will; with 6. will be late for; sleeps late 7. has time; will help 8. will; fails 9. won’t be; copy |
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