If引导的从句

1、年 级初二学 科英语版 本外研社（新标准）课程标题If引导的从句编稿老师李晶一校林卉二校黄楠审核刘晓军一、学习目标1. 掌握if引导的宾语从句的用法。2. 掌握if引导的条件状语从句的用法。3. 能恰当使用含有if引导的条件状语从句的复合句中主从句的时态。二、重点、难点1. 含有if引导的条件状语从句的复合句中主从句的时态。2. If引导的宾语从句与条件状语从句的区别。 三、考情分析通常在单项选择、完形填空或补全、完成句子等题型中考查，分值约34分。四、知能提升（一）知识讲解【认知讲解】I. if引导的宾语从句if 引导宾语从句时，意思为：是否，从句的时态通常要和主句保持一致。【例句】I wa

2、nt to know if he lives there.我想知道他是否住在那儿。He asked me if I could help him.他问我是否能帮他。【考查点】if、whether引导的宾语从句的区别1. if或whether引导宾语从句时，作“是否”讲，常放在动词ask、see、say、know和find out等后面。一般情况下，两者常可换用，在口语中多用if。【例句】 Nobody knows whether / if it will rain tomorrow. 没有人知道明天是否下雨。 Lucy asked whether / if they had a cotton

3、sweater. 露西问他们是否有棉制的毛衣。2. if或whether引导宾语从句时，要注意三个方面，即连词、语序和时态。if或whether既不能和that 或其他连词（副词）同时使用，也不能省略。【例句】我不知道他今天是否会来。误 I dont know that if(whether) he will come here today.正 I dont know if(whether) he will come here today.他走过来看看猫是否出了毛病。误 He came to see what if (whether) there was anything wrong with

4、 his cat .正 He came to see if (whether) there was anything wrong with his cat .if或whether引导宾语从句时，虽具有疑问的意义，但其从句应用陈述句的语序。【例句】 Did you know the way to the hospital? The old woman asked me.The old woman asked me if / whether I knew the way to the hospital.老妇人问我是否知道去医院的路。 if或whether引导的宾语从句应和主句的时态保持一致。即主句

5、为一般现在时，从句用任一种时态；主句为一般过去时，从句则用过去时中的任一种时态。【例句】 I dont know if (whether) he has come here. 我不知道他是否来过这儿。Tom asked if (whether) I had read the book. 汤姆问我是否看过这本书。3. 只能用whether的情况在动词不定式之前只能用whether：【例句】I cant decide whether to stay.我不能决定是否留下。在whether or not 的固定搭配中：【例句】 I want to know whether its good news

6、or not. 我想知道它是不是好消息。在介词后，只能用whether：【例句】 His father is worried about whether he loses his work. 他的父亲担心他是否会失去工作。用if会引起歧义时：【例句】Could you tell me if you know the answer? 这句话有两种意思：“你能告诉我你是否知道答案吗？”或“如果你知道答案，请告诉我，好吗？”。如用whether则可避免歧义。 【考题链接】I dont know _ they could pass the exam or not.A. why B. if C. tha

7、t D. whether答案：D解题思路：本题考查if与whether的区别，在whetheror not的固定搭配中通常只用whether。II. if引导的条件状语从句1. 含义条件状语从句是在复合句中作条件状语的句子。表示假如有从句的动作发生就会有主句的动作发生，条件状语从句常由从属连词if引导。【例句】You will catch the bus if you get up early.如果你早起的话，就能赶上公共汽车。2. 类别主祈从现：主句是祈使句, 从句是由if引导的使用一般现在时的句子。【例句】 If you want to go, please tell me. 如果你想去，

8、请告诉我。Print the photo if you like it. 如果你喜欢这照片就把它打印出来。主将从现：指if引导的条件状语从句用一般现在时，主句用一般将来时。【例句】 If it doesnt rain tomorrow, well go to the Great Wall.如果明天不下雨，我们就会去长城。 If you dont get up early, you will be late for school. 如果你不早点起床，你上学就会迟到。3. if引导的条件状语从句用法：（1）位置if引导的条件状语从句，既可放在主句之前也可放在主句之后。当从句置于主句之前时，常用逗号

9、与主句隔开。【例句】You will catch the bus if you get up early.=If you get up early, you will catch the bus.如果你早起的话，就能赶上公共汽车。（2）时态应遵循主、从句时态呼应的原则。当主句是一般现在时（包含祈使句和含情态动词can, may, must等的句子），从句也用一般现在时。【例句】You must see the doctor if you are ill.如果你生病了，你必须去看医生。If you want to go skating, wear warm clothes.如果你想去溜冰，穿上暖

10、和的衣服。如果主句是一般将来时，从句必须用一般现在时。【例句】 You will be late for school if you get up late.如果你起晚了，你上学将迟到。If it rains tomorrow, we wont go to the Great Wall.如果明天下雨，我们就不去长城了。（3）在if引导的条件状语从句中，当主句是一般将来时时，不能使用be going to结构，而要用will。【例句】Ill help you with your English if I am free tomorrow.如果明天我有空，我会帮助你学英语。（4）在if引导的条件状

11、语从句中不能使用some，而要用any。【例句】If you have any questions to ask, please come to my office.如果你有问题要问的话，请到我办公室来。（5）同义句转换if引导的条件状语从句可转换成简单句，其方法如下：* 借助“祈使句+and/ or+简单句”结构。其中and表示句意顺承，or表示句意转折。【例句】If you work hard, youll pass the exam.=Work hard, and youll pass the exam.如果你努力学习，你就会通过考试。If you dont hurry up, youl

12、l be late.= Hurry up, or youll be late.如果你不快点，你将会迟到。*借助介词with 或without来转换。【例句】If you help me, Ill finish my job soon.=With your help, Ill finish my job soon.如果你帮我，我将很快完成我的工作。If there is no water, fish may die.= Fish may die without water.如果没有水，鱼可能会死。另外，if从句还表示不可实现的条件或根本不可能存在的条件，即一种虚拟的条件或假设。从句多用一般过去时

13、或过去完成时，表示对现在或过去的一种假设。【例句】If I were you，I would invite him to the party如果我是你，我会邀请他参加聚会。 I would have arrived much earlier if I had not been caught in the traffic要不是交通堵塞，我会来得更早一些。4. 口诀：if 条件句不一般，几个要点记心间； 条件句，放在前，逗号要放句中间。 条件句表可能，主句多用将来时； 条件句表事实，主句常用现在时。 III. If引导的宾语从句和条件状语从句的区别if引导条件状语从句时意为“如果”，引导宾语从句时

14、意为“是否”，可用whether替换。【例句】1) We will go out if it is fine tomorrow. 如果明天天好，我们就出去。2) I dont know if the train has arrived. 我不知道火车是否已经到达。句1)中if引导的是状语从句。这个从句表示“条件”。句2)中if引导的是宾语从句，充当谓语动词dont know的宾语。【考题链接】 I dont know _ he will come tomorrow. _ he comes, Ill tell you A. if; Whether B. whether; Whether C. i

15、f; That D. if; If答案：D解题思路：第一个空处为宾语从句的引导词，用if、whether都可以；第二个空为条件状语从句的引导词，需用if，综合考虑，D项正确。（二）提分技巧1. 熟练掌握if引导的宾语从句与条件状语从句的特点。 2. 熟知if引导的宾语从句与条件状语从句引导词的区别。 （三）即学即练I. 句型转换 1. Do they want fried chicken? He asked the boys.(改为宾语从句) He asked the boys _they _fried chicken. 2. Was the watch made in Shanghai? I

16、 dont know.(改为宾语从句) I dont know _the watch _made in Shanghai.3. “Do you want to try something new?” Toms mother asked him.(同义句转换)Toms mother asked him _to try something new.答案：1. if / whether, wanted 2. if / whether, was 3. if / whether he wanted II. 用括号中所给动词的适当形式填空1. If it _ (not rain)tomorrow, _(l

17、et) us go shopping.2. Please _ (tell)me if you _ (go).3. If you _ (be)ill, you _ (have)to see the doctor.4. I _ (leave)for Beijing if it _(not snow) this afternoon.答案：1. doesnt rain, let 2. tell, go 3. are, have 4. will leave, doesnt snowIII. 将下列句子翻译成英语。1. 如果明天不下雨，我就和同学们去野餐。_.2. 如果周日你去购物的话，我就去。_.3.

18、如果你想减肥（lose weight），就锻炼身体吧。_.4. 如果冬天来了，春天还会远吗？_.5. 如果可能的话，我就去火车站接你。_.答案：1. If it doesnt rain tomorrow, I will have a picnic with my classmates.2. I will go shopping on Sunday if you do.3. Take some exercise if you want to lose weight.4. If winter comes, can spring be far behind?5. If (it is) possibl

19、e, Ill meet you at the train station.下学期期中复习（一）一、预习新知Module 1-Module 5重点基础知识二、预习点拨思考问题一：能否先把这5个模块的重点单词、短语、语法整理一下？思考问题二：我们已经学习了哪些语法？哪些还是你比较薄弱的？（答题时间：45分钟）一、用所给动词的适当形式填空。 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

20、, 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.

21、 Peter _(send) me a beautiful souvenir if he _(tour) 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) busy?13. He _(write) a letter to his grandparents if he _(get) his rep

22、ort 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.二、完成句子（每空一词）。1. 如果你要过马路，不要乱跑。_ _ around if you cross the road.2. 明天如果下雨的话，我们将呆在家里。We _ _ at home if it _ tomorrow.3. 如果你能说好英语的话，你就可以容易地与外国人交谈。If yo

23、u can _ English well, you _ _ _ foreigners easily.4. 如果你对别人好，人们也会对你好。If youre nice to people, they _ _ _ to you, too.5. 如果学生不对考试如此担心的话，他们会更开心的。If students dont worry about exams so much, they _ _ _.6. 他如果电视看太多了，他的父母会不高兴。If he _ TV too much, his parents _ _ unhappy.7. 如果我们为他组织生日聚会，大家都会来的。Everyone _ _

24、 if we _ a birthday party _ him.8. 如果明天不下雨，我会和你一起去公园的。If it _ _ tomorrow, I _ go to the park _ you.9. 如果他有空，他会帮助你的。If he _ _, he _ _ you.10. 如果Tom考试不及格，他就没有机会上高中了。Tom _have the _to go to the senior high school if he _ _ the exams.三、同义句转换。1. Study hard, or you wont pass the exam.If you study hard, yo

25、u _ _ the exam.2. Take a taxi, and youll catch the train._ you _ a taxi, youll catch the train.3. If you go to bed early, you wont feel tired in the morning._ _ _ early, _ you wont feel tired in the morning.4. If you dont work hard, your teacher will probably be angry._ _, _ your teacher will probab

26、ly be angry.5. Breathe deeply for one minute, and youll feel relaxed._ you _ deeply for one minute, you _ _ relaxed.四、阅读下面的广告，然后用“if., .will.”的句式回答问题。Travel BrochureCheap Cheap Cheap. Beijing for the weekend. 3D/2N. Book Now.Five Star HotelSave 50%Four Star HotelSave 40%Three Star HotelSave 30%Book

27、before December 31st. Breakfast Included.City Tour 50RMB. Visit the Great Wall 100 RMB.1. How much will you save if you stay at the Four Star Hotel?_2. How much will you save if you stay at the Three Star Hotel?_3. What will happen if you book after December 31st?_4. How much will you have to pay if

28、 you want to go on the City Tour?_5. How much will you have to pay if you want to visit the Great Wall?_五、单项选择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 finis

29、h D. before, finishes3. What will father _ us from Japan? A. take B. bring C. carry D. make4. 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 askC. would tell, ask D. will tell, asks6. What are you going to do tomorrow? W

30、ell 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 come8. What will you do if you _ to the old folks home visit?A. go B. went C. go

31、ing 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. has

32、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 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. wer