1、1条件句【条件句】 （一） 真实条件句连接词 条件从句 结果从句一般将来时- 表可能： If he runs, hell get there on time. may/ might/ can-允许/能力：If it stops snowing, we can go out.must/ should-命令，请求，劝告：If you want to lose weight, you must/ should eat less bread.If If + 主语 + 一般现在时一般现在时- 客观事实： If you heat ice, it turns to water.（二）虚拟条件句虚拟语气表示一
2、种假设的情况，或一种主观的愿望，即动词所表示的动作或状态并非事实，或不可能实现。英语虚拟语气的形式有下列几种： 一、与现在事实相反 连接词 条件从句 结果从句If If + 主语 + 一般过去时（ be 动词一般用were） 主语+ should/would/ could/ might +动词原形如：If he had the time, John would make a trip to China to see the Great Wall.If I were you, I would give up drinking immediately(立即、立刻). If I didnt have
3、 a cold, I would go to your birthday party.二.与将来事实相反如：If you should lose, what would you do?If I were to see her tomorrow, I would tell her the truth.三、与过去事实相反连接词 条件从句 结果从句If If +主语+过去完成时（ had+过去分词） 主语+should/would/could/might+ have+过去分词如：If Id known that it was going to rain, I would never have gon
4、e for a walk in the country.If I hadnt had a cold last week, I wouldnt have missed your birthday party.连接词 条件从句 结果从句If If + 主语 + should/would/were to+动词原形 主语+ should/would/ could/ might +动词原形2例题 ( )1. I dont know if it _tomorrow. If it _,we wont go on a picnic.A. rains;rains B. will rain;rains C. wi
5、ll rain;will rain( )2. In summer , food goes bad easily _ it is put in the refrigerator.A. until B. if C. unless( )3. -I hear Jack Chan will come to Laiwu next week.-Really? _ he comes, my younger sister will be very happy,AIf BUntil CUnless DBefore( )4. Could we play football in your playground, Si
6、r ?-No,_ you have the principals note.A.if B.unless C.because D.since( )5. Many children like fried chicken _it is unhealthy food.A.if B.because C.although( )6. All the students in Class 5 will climb the mountain if it _ rain tomorrow.A. wont B. dont C. didnt D. doesnt( )7 -Would you like to go bike
7、 riding with us tomorrow?-Sure, _ I am busy.A. since B. unless C. when D. until( )8. I dont like bread. I wont eat it _ I am very hungry.A. when B. unless C. if( )9. Youd better look up the new word in a dictionary _ you dont know it.A. if B. that C. though D. whether( )10. After the meeting, we wil
8、l have a party. If you _ free, come and join us.A. are B. will be C. were练习 ( )1. Ill go for a walk with you if it _ tomorrow.A. wont rain B. doesnt rain C. will rain D. not rains( )2. Im waiting for my Mum. _, Ill go shopping with her.A. If she doesnt come B. If she comes C. If she will come D. If
9、she wont come( )3. -Tommy, do you know if Frank _ to the zoo this Sunday if it _? -Sorry, I have no idea. A. will go; is fine B. goes; is fine C. will go; is going to be fine D. goes; will be fine ( )4. If I _ you, I would wear the shirt and the tie.A. am B. was C. were D. will be( )5. What would yo
10、u do if you _ a lot of money? A. had B. have had C. will have D. have3( )6. In Britain, you must be 18 _ you want to drive a car.A. why B. because C. so D. if( )7. If I _ you, Id take the small apple. A. am B. were C. was( )8. Susan will not arrive at the airport on time _ she hurries up.A. once B.
11、if C. when D. unless( )9. If my father _ back, please let me know.A. comes B. will come C. come ( )10. Lets see _we can find some information about the city.A. that B. if C. what D. which( )11.If I you, I a big house.A. was, would buy B. were, would like to buy C. were, would buy D. was, bough( )12.
12、If he tomorrow, please tell me.A. come B. comes C. will come D. came( )13.What would you do if you the lottery( 彩票)?A. win B. won C. are going to win D. have won4典型例题1B 2C3A4B5C6D7B。考查 unless 引导的条件状语从句。由关键词 Sure 可推断“我会和你们一起自行车旅行的，除非我很忙”，故排除 A、C 、D 三项，选 B。8B9A。考查 if 引导的条件状语从句。结合题意 “如果你不知道那个新词，你最好在字典里
13、查阅它 ”可排除B、C、D 三项，选 A。10A课后练习1B。在条件状语从句中，从句不能用一般将来时，应用一般现在时，故正确答案为B 。2B3A。结合题意“汤姆，如果天气好的话，你知道弗兰克这个星期六将去动物园吗？ ”可知第一个空是宾语从句，要用一般将来时，第二个空是条件状语从句，要用一般现在时，故排除 B、C 、D 三项，选A。4C5A。四个选项分别是动词 have 的四种形式，由关键词 would 和题意“如果你有很多钱，你会做什么”可知这里考查虚拟语气，故选 A。6D7B。本题考查虚拟语气的用法。表示与现在事实相反的假设，条件状语从句中的 be 须用 were。8D9A。考查条件状语从句的时态。因为主语是祈使句，所以从句要用一般现在时，故选 A。10B 11C 12B 13B5
