If 引导的一般条件状语从句条件状语从句概念：在复合句中，由从句表示的状语叫做状语从句。
它可以用来修饰主语中的动词.形容词.副词等。
根据它表达的意思，状语从句可以分为时间状语从句，地点状语从句，条件状语从句，比较状语从句，目的状语从句，结果状语从句和让步状语从句等。
由连接词if或unless引导的状语从句叫做条件状语从句。
（注意：在含有条件状语从句的复合句中，如果主句是一般将来时态，从句要用一般现在时[主将从现原则])经典语句：If it doesn't rain tomorrow, we will go to the zoo. If you open the door，I will come in.if 引导的条件状语从句主句用一般将来时，if 从句用一般现在时。
We will go to the park if it is fine tomorrow.如果明天天好的话我们就去公园。
We will go traveling if we have time tomorrow.如果明天我们有时间我们就去旅行。
主句祈使句，if 从句用一般现在时。
Please call me if you need help. 如果你需要帮助请打电话给我。
Sing a song if you feel happy. 如果感到快乐就唱首歌吧！主句含有情态动词，if 从句用一般现在时。
Y ou can make a lot of money if you run a company.如果你经营一家公司的话你会装很多钱。
Y ou can get number one if you study hard. 如果你努力学习你就可以得第一。
—Mary, what about going boating if it doesn’t rain? 玛丽，如果明天不下雨，我们就划船好吗？—Good idea. 好主意。
1、主将从现：主语将来时，从句一般现在时，例：If it is rainy tomorrow，（从句）I will stay at home。
（主句）2、虚拟：主句用would do，从句用过去式，具有假设性，一定不会是真的，例如“如果我是你，我不会穿那条裤子”If I were you，I would not wear the pants。
我永远都不可能是你，所以是具有假设性的，还有“如果你有一百万，你会怎么做？”突然天降横财机率是很小的，所以也是具有假设性的，像这种几乎不可能发生的事或者根本不会发生的事就用虚拟！条件状语从句和主句还有一个共同的伙伴，有时它可以替代从句和主句，它就是“祈使句+and / or+简单句”。
其中and表示句意顺承；or则表示转折，意为“否则”。
例如：If you work harder, you’ll pass the exam.= Work harder, and you’ll pass the exam. 如果你再努力些，你就会通过考试。
If you don’t hurry up, you’ll miss the train.= Hurry up, or you’ll miss the train. 如果你不快点儿，你就赶不上火车了。
在学习条件状语从句时，同学们要注意以下几点：一、时态如果主句是一般将来时态，这时从句不可以用将来时态，而要用一般现在时。
例如：I won’t go there with you if it rains tomorrow. 如果明天下雨的话，我就不和你一起去那儿了。
二、主从句的位置大多数情况下，从句可以位于主句之前，也可以位于主句之后。
不过从句在前时，主从句之间必须用逗号隔开。
例如：Please tell me if he comes back.= If he comes back, please tell me. 如果他回来了，请告诉我一声。
词的适当形式填空1. If you wear jeans, we ____________ (not let) you in.2. If you go to the party, you ______________ (have) a great time.3. If he ___________ (come) tomorrow, I ____________(call).4. What _______ you _______ (do) if you ________ (be ) A teacher?5. Look at the clouds. It _________ (rain).6. Kate usually __________ (watch) TV on Sundays.7. Listen! Who ___________ (sing) in the next room?8. They ___________ (get) to Shanghai two days ago.9. If it __________ (be) fine next Sunday, we _________ (help) the farmers pick apples.10. How soon ________ you ________ (finish) the work?11. Let me ________(tell) you _______ (say) it like this.12. Don’t make any noise. The baby ________- (sleep) now.13. It _________ (take) me half an hour __________(learn) this text by myself yesterday.14. He with his friend ________ (go) to help Grandma Li three times a week.15. My mother is watering these _____________ (flower).16. If you _________(stay) at home tomorrow, you’ll see him.17. If you drive to Shanghai next week, your parents______________(be ) angry.18. If he ___________(ride) his bike to go to school tomorrow, he will be late.19. If it ____________ (not rain) tomorrow, we will meet you.20. If you ____________ (not help) me, I won’t let you come in.21. Do you know what _________-(happen) in ten years.22. There __________ (be) a speech by our headmaster tomorrow afternoon in our school.根据括号内的要求，改写下列各句，每空一词。
1. I’ll go to your birthday party if I’m free.（对划线部分提问）_______ will you ________ if you are free?2. They’ll ask you some questions.（一般疑问句）_______ they ask you ________ questions?3. If I’m a teacher, ___________________________（完成句子）4. If he doesn’t help me, I won’t buy the car,（改为简单句）I won’t buy the car___________ __________ help.翻译下列句子1.如果我明天有时间，我就和你一起玩。
If I ___ ____ tomorrow, I _____ _____ with you.2.今天晚上如果有足球赛，他们就不上学了。
If there ___ a football match, they _____________to school.3.如果明天不下雨，我们就去公园。
If it _____ ____ tomorrow, we _____ ___ to the park.1.If you _____ to the party, you’ll have a great time. A. will go B. went C. go D. going2．I ____ her the answer if she ____me.A. can tell, will askB. will tell, will askC. would tell, askD. will tell, asks3. – What are you going to do tomorrow?--We’ll go to the library tomorrow if it ___.A. isn’t rainB. rainC. won’t rainD. doesn’t rain4.—Do you know when he will come back tomorrow?--Sorry, I don’t know. When he ____ back, I’ll tell you.A. comesB. will comeC. comeD. may come5. What will you do if you _____ to the old folk’s home visit?A. goB. wentC.goingD. will go6. If I eat ____ food, I’ll be very fat.A. too manyB. many tooC. too muchD. much too7. I’ll give the book to him if he ___ here next Sunday.A. will comeB. comesC. is comingD. came8. There ____an English film in our school tomorrow.A. is going to haveB. will haveC. is going to beD. has9. Could you tell us where ____？A. will the next Olympic Games heldB. the next Olympic Games will be heldC. would the next Olympic Games be heldD. the next Olympic Games would be held10. When my mother returned last night, I ____ a book.A. readB. am readingC. was readingD. am going to read11.What ____ you ____ when it began to rain?A. do, doB. were, doingC. are, doingD. did, do12. I’ll wake you up when he ____back.A. willB. is going to comeC. comesD. come二、用所给词的适当形式填空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, 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 ____(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 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.III完成句子1.如果他到的晚了会发生什么事情？What _______________ if he _____________ late?2. 如果努力学习，你就会取得好成绩。