if引导的条件状语从句讲解和练习(答案)

1、条件状语从句条件状语从句通常由 if （如果）,unless （除非），as long as （只要）引导例如：If it rains tomorrow, we won go to the park. 女口果明天下雨，我们就不去公园了。Uni ess weather stops me, I go for a walk every.我每天都会去散步，除非遇上坏天气。Our pare nts will be pleased with our performa nee as long as we try our best.小试牛刀：1、只要我们竭尽全力，父母就会满意我们的表现。Our pare nt

2、s will be pleased with our performa nee_ we try our best.2、如果人人为保护环境做出贡献，世界将会变得更美好。_ to proteeti ngthe environment, the world will become much more beautiful.二、if 引导的条件状语从句（1） “i 从句+祈使句”勺句子。其实，if 作为一个连词，主句也可以是其他形式的句子。 例如：If you want to go, pleaselet me know.If the gree n light is n ton, wait for a m

3、inute.祈使句+ and （or）+ 陈述句”在意思上相当于一个带有条件状语从句的复合句。注意：A.祈使句+ and +陈述句”可以转化为 if 引导的肯定条件状语从句，而且主语是第二人称。B.祈使句+ or +陈述句”可以转化为 if 引导的否定条件状语从句，而且主语是第二人称。例如： Study hard and you will pass the exam. =If you study hard, you will pass the exam.Hurry up, or you ll be late. =If you don t hurry up, you ll be late.考题（

4、2010 重庆中考）Work hard , _ you may eateh up with your classmates soon.A.orB.butC.a ndD.yet思路解析：本句是 祈使句+ and”的句型，句意为 努力学习，你会很快赶上其他同学的”，and 在句中表示承接关系，所以选 C 项。答案：C黑色陷阱：本题的陷阱是句型，本句型区别于祈使句+ or”，这个句型的含义是“；不然的话/否则”。绿色通道：祈使句后面既可以加 and，也可以加 or，所以要全面分析句意，再作决定。小试牛刀：用 if 连接下列句子1、Go to bed early and you will have a

5、 good rest.2、Hurry up, or you ll miss the bus.三、if 从句与主句具有以下特点：1.If 从句中用一般现在时；表示未来的一种条件，从句中可以加时间状语。e.g.If you can t eome tomorrow, we can hold the party a little later.明天你如果不能来，我们可迟一点举行宴会。If it doesn t rain tomorrow, we ll go to the Great W 天如果不下雨，我们就去长城。2 .当 if 表示未来的条件时，主句中用一般将来时，从句用一般现在时，即“主将 _。表示

6、如果某种条件存在，就有可能/不可能发生什么事情。e.g.If you don t get up early, you will be late for school.你如果不早点起床，上学就会迟至 U。If I play games on it, it will go wron g.如果我用它玩游戏，它就会坏掉。3 . if 从句可放在主句前或主句后，从句置于主句前时，须用逗号与主句隔开，反之则不用逗号。e.g.If it s fine tomorrow, we can go out. 女口果明天天气好，我们就能出去。She will be happy if she joi ns the pa

7、rty.如果她参加聚会她会很开心的。I ll ask the teacher for help if I don t ur 如果我不懂我会求助老师的。三.注意 if 引导的条件状语从句和宾语从句的区别if 可以用来引导宾语从句也可以用来引导条件状语从句，主要是要弄清if 引导从句的时态。if 在引导宾语从句时，意为“是否”。要根据实际情况来确定时态，而if 在引导条件状语从句时意为“如果，假设”，要用一般时代替将来时，即“主将从现”。e.g .I want to know if he will come here tomorrow.我想知道他明天是否至 U 这儿来。（if 在上句引导的是宾语从

8、句，从句中有很明显的表将来的时间状语tomorrow，所以 if 从句要用一般将来时。）e.g.If it rains tomorrow, we ll put off the sports meeting.女口果明天下雨，我们就推迟运动会。（if 在上句引导的是条件状语从句，尽管从句中也有表将来时的时间状语tomorrow，从理论上讲也应该用一般将来时，但是在 if 引导的条件状语从句中要用一般现在时代替一般将来时，故从句谓语用 rains 而不用 will rain.）二、典题分析1、（2010 上海）We will have no water to drink _ we don prote

9、ct the earth.A. un tilB. beforeC. thoughD. if答案D .解析if 引导条件状语从句，表示“如果”。意思是如果我们不保护地球，我们将会没有水喝。2、 （2011 重庆）We will plant trees tomorrow, and I dontknow _ Tom will come and join us.A. if B. which C. whatD. where答案A .解析if 引导宾语从句，表示“是否”。意思是我们明天将会去植树，但是我不知道Tom 会不会去。3、 一 Do you know if _ finished the work?

10、 Not yet. If he _, he will give me a call.A. he will finishB. he finishesC. he , finishesD. he ll, will finish答案C .解析问句的 if 引导宾语从句，表示“是否”，从句要用陈述语序，从答句Not yet.中可以看出从句应该用现在完成时态，答句的if 引导状语从句，要遵循主将从现的规律。练习一、用 if 连接下面的句子:1、 You do not un dersta nd the article. Ask your teacher.2、 You want to know more ab

11、out it. Please call your teacher.C . will the train leaveD . the train leaves3、Tell him to make a phone call to me. He will come here tomorrow.4、You want to go. Please tell me.5、Look at our website. The camera does not work.二、用所给的提示词组成一个if 引导的条件状语从句。1、 be tired, have a rest (Tom)2、 not go to bed ear

12、ly, feel sleepy (you)3、 become un healthy, not eat vegetables(childre n)4、 no t liste n to the teacher, not study well(I )5、fall behi nd others in study ing, spe nd too much time on the games(Da Wei)、单项选择:1. You are sure to pass the exam_you study hard.A. if B. though C. that D. since2. Ill go to se

13、e the film with you_I have time this eve ning.A. whether B. so C. if D. whe n3._ you study harder, youll never pass the final exam.A. If B. Un tilC. Un less D. Except4 . We ll stay at home if it_this after noon.A. rainB. rains C. to rainD. raining5 . We will go to the Great Wall if it_ tomorrow.A. w

14、on t rain B . isn t raining6 . I don t know if he_ .He will come if it_ .A . comes; won t rainC . comes; does nt rain7 . Do you know what time_?A . the train leaveC . rained D . doesn t rainB . will come; doesn t rainD . will come; won t rainB . does the train leave8 . Do you think if_ an English fi

15、lm tomorrow night?A.is thereB.there is going to haveC .there is going to beD. will there be9. Will you please tell me?A. where Pudong Airport isB . how far Pudong Airport wasC .how can we get to Pudong AirportD . when was Pudong Airport built10.Mike wants to know ifa picnic tomorrow.Yes. But if it_

16、, we ll visit the museum in stead.A.you have; will rainB.you will have; will rainC.you will have; rainsD.will you have; rains11 .Why didn t Nick come to school yesterday ?_ he was ill.A. AfterB.WhereC.WhenD . Because12 . This box isheavy1 cant carry it.A. too; toB.so; thatC .very; thatD . too; that1

17、3 . I don t knowhe still lives here.A. whereB.whatC .whe nD . whether14.-Do you know if heto play basket ball with us?-I thi nk he will come if he_free tomorrow.A. comes; isB. comes; will beC. will come; isD. will come; will be15. In the zoo if a child_into the water and can t swim, the dolphins may

18、 come up_ him.A. will fall; to helpB. falls; to helpC. will fall; helpD. falls; helpi ng16n the bookshop , a reader asked the shop keeper_ Who Moved My Cheese was an interesting book.A.thatB.howC.whatD.if17、 I want to know_ you have a brother.A.if B.that C.those D.them18、 We will go hiking if it _ tomorrow.A.will be fine B.is fine C.be fine D. is gong to be fine19、 Maybe you _ i