2020年八年级英语上册if引导的条件状语从句讲义（新版）人教新目标版 5页

if 引导的条件状语从句（讲义）‎ 状语 用来表示行为发生的时间、地点、目的、方式、程度等，通常由副词或介词短语充当，也可由一个句子充当。‎ I slept at home yesterday because I had a bad cold.‎ 状语从句 状语从句指句子作状语。‎ 根据其作用可分为时间、地点、原因、条件、目的、结果、让步、方式等从句。‎ 状语从句一般由连词(从属连词)引导。‎ I will go to school by bike tomorrow if it is sunny.‎ Grammar focus ‎—I think I’ll take the bus to the party.‎ ‎—If you do, you’ll be late.‎ If you take the bus to the party, you’ll be late.‎ ‎—I think I’ll stay at home.‎ ‎—If you do, you’ll be sorry.‎ If you stay at home, you’ll be sorry.‎ ‎—What will happen if they have the party today?‎ ‎—If they have it today, half the class won’t come.‎ ‎—Should we ask people to bring food?‎ ‎—If we ask people to bring food, they’ll just bring potato chips and chocolate.‎ 1. if 在本单元句中意为“ ； ” ，用于引导 ‎ 。‎ 即 if 引导的是一个完整的句子，所以一定要有主谓，成为从句，另一个句子则成为主句。‎ If you go there, I’ll go, too.‎ We will go hiking if it doesn’t rain tomorrow.‎ If Bob leaves tomorrow, I will hold a party for him tonight.‎ 2. if 引导的条件状语从句既可以放在主句前，也可放在主句后。但是如果放在主句前，即句首时，从句后面要用 与主句隔开。‎ 3. 3‎ You will keep healthy if you do more exercise. If you do more exercise, you will keep healthy.‎ 1. 时态：if 引导的条件状语从句用 表示将来，‎ 主句可以使用一般将来时，含有情态动词的句子或者祈使句。主将从现 If you practice speaking English more, you will like it better. If she goes to New York tomorrow, I will go there, too.‎ My sister will be very happy if our uncle comes next week.‎ 练习：‎ If Nancy the exam, she will go to Australia for English study.‎ A. pass B. passed C. passes D. will pass If the weather fine, we have a sports meeting next weekend.‎ A. will be; will B. is; will C. was; would D. was; will 主情从现 If you get up at six tomorrow morning, you can catch the first bus. If you go to study in America next year, you must learn English hard.‎ 主祈从现 Let’s go out for a walk if it doesn’t rain tomorrow. If you see a snake in the forest, don’t move!‎ unless 也可引导条件状语从句，表示“如果不，除非” Unless he comes here in an hour, I will go there alone. If he doesn’t come here in an hour, I will go there alone.‎ You will feel worse unless you go to see the doctor right now. You will feel worse if you don’t go to see the doctor right now. 练习：‎ ‎ you read it, you can’t imagine how interesting the story is.‎ A. Unless B. Because C. Although D. If ‎—Please give Alice the story book you see her.‎ ‎—All right.‎ A. unless B. or C. but D. if B. 3‎ Exercises 一、单项选择 ‎( )1. Studying in groups is necessary you want to do well in school.‎ A. if B. until C. unless D. though ( )2. —Will you help me with the trouble?‎ ‎—I won’t you tell me the truth.‎ A. if B. but C. after D. unless ‎( )3. If Bob away from the junk food, he will be in good health.‎ A. stay B. will stay C. stays D. stayed ( )4. If Tom the game, we’ll give him a surprise.‎ A. win B. wins C. won D. winning ( )5. We’ll go to the park if it tomorrow.‎ A. won’t rain B. don’t rain C. doesn’t rain D. rain ( )6. If you’re more careful, you much better.‎ A. do B. will do C. are doing D. did ‎( )7. If there no buying and selling of animals, there ‎ no killing in nature.‎ A. is; will be B. will be; will be C. is; is D. will be; is ‎( )8. I’m waiting for my friend. If he , I ‎ swimming alone.‎ A. doesn’t come; go B. won’t come; go C. won’t come; will go D. doesn’t come; will go 二、翻译 9. 如果明天不下雨，我会去看你的。‎ If it tomorrow, I you.‎ 10. 如果 Mary 不为考试做准备，她会不及格。‎ If Mary the exam, she fail the exam.‎ 11. 如果你不告诉我原因，我会告诉妈妈这件事。‎ 12. 我不会去医院的，除非你和我一起去那儿。‎ 3‎ ‎【参考答案】‎ Grammar focus 1. 如果；假如；条件状语从句 2. 逗号 3. 一般现在时主将从现 练习：‎ C B unless 练习： A D Exercises 一、单项选择 ‎1-5 ADCBC 6-8 BAD 二、翻译 9. doesn’t rain; will visit 10. doesn’t prepare for; will 11. If you don’t tell me the reason, I will tell mom this thing.‎ 12. I won’t go to the hospital unless you go there with me.‎ ‎4‎