If引导的条件状语从句[课本链接]If you do, you’ll be sorry. (Unit 5, Section A)[定义]条件状语从句通常由if（如果），unless（除非），as long as（只要）引导。
if引导的条件状语从句表示假如从句的动作发生，主句的动作就（不）会发生。
[句子结构]中考考点之[时态呼应]在复合句中：⑴当主句是一般现在时或是一般将来时时；（2）当主句是祈使句时；（3）当主句含有情态动词时，if引导的条件状语从句通常用一般现在时。
如：例句：If she doesn’t come, she will be sorry. 如果她不来，她会遗憾的。
Have a good rest if you are tired. 如果累了，你就好好休息一下。
We must study hard if we want to pass the final exam. 如果想通过期末考试，我们必须努力学习。
[同义句转换]1. If引导的条件状语从句可以用“祈使句，＋and / or ＋一般将来时的句子”转换。
祈使句,+and+陈述句可以转化为if 引导的肯定条件状语从句。
祈使句,+or+陈述句可以转化为if 引导的否定条件状语从句。
如：If you work hard, you’ll pass the exam easily. → Work hard, and you’ll pass the exam easily. 努力学习，你将很容易通过考试。
If you don’t hurry up, you’ll miss the train. → Hurry up, or you’ll miss the train. 快点儿，否则你就赶不上火车了。
真题(2010重庆中考)Work hard，________ you may catch up with your classmates soon.A.orB.butC.andD.yet课后练习：用if连接下列句子1、Go to bed early，and you will have a good rest.2、Hurry up, or you’ll miss the bus.2. 用含介词with或without的介词短语转换。
如：If there is no water, fish can’t live. → Fish can’t live without water. 离开水，鱼不能生存。
[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，并且一般将来时用will+ V.原形；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到这儿来。
（if在上句引导的是宾语从句，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.如果明天下雨，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. ）典题分析1、（2010上海）We will have no water to drink we don’t protect the earth.A. untilB. beforeC. thoughD. if2、（2011 重庆）We will plant trees tomorrow, and I don’t know Tom will come and join us.A. ifB. whichC. whatD. where3、—Do you know if finished the work? —Not yet. If he , he will give me a call.A. he’s, will finishB. he’ll, finishesC. he’s , finishesD. he’ll , will finishHomework一、用if 连接下面的句子：1、 You do not understand the article. Ask your teacher.2、 You want to know more about it. Please call your teacher.3、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 early, feel sleepy (you)3、 become unhealthy, not eat vegetables (children)4、 not listen to the teacher, not study well (I )5、 fall behind others in studying, spend too much time on the games (Da Wei)三、单项选择：1. You are sure to pass the exam ___ you study hard.A. ifB. thoughC. thatD. since2. I'll go to see the film with you___I have time this evening.A. whetherB. soC. ifD. when3. ___ you study harder, you'll never pass the final exam.A. IfB. UntilC. UnlessD. Except4．We’ll stay at home if it ______ this afternoon.A．rain B．rains C．to rain D．raining5．We will go to the Great Wall if it ______tomorrow.A．won’t rain B．isn’t raining C．rained D．doesn’t rain6．—I don’t know if he ______.—He will come if it ______.A．comes; won’t rain B．will come; doesn’t rainC．comes; doesn't rain D．will come; won’t rain7．Do you know what time ______？A．the train leave B．does the train leaveC．will the train leave D．the train leaves8．Do you think if______ an English film tomorrow night？A．is there B．there is going to haveC．there is going to be D．will there be9．Will you please tell me ______？A．where Pudong Airport is B．how far Pudong Airport wasC．how can we get to Pudong Airport D．when was Pudong Airport built10．—Mike wants to know if______ a picnic tomorrow.—Yes. But if it ______, we’ll visit the museum instead.A．you have; will rain B．you will have; will rainC．you will have; rains D．will you have; rains11．—Why didn’t Nick come to school yesterday？—______ he was ill.A．After B．Where C．When D．Because12．This box is ______ heavy ______ I can’t carry it.A．too; to B．so; that C．very; that D．too; that13．I don’t know ______ he still lives here.A．where B．what C．when D．whether14. ---Do you know if he _______ to play basket ball with us?---I think 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 come up ______ him.A. will fall; to helpB. falls; to helpC. will fall; helpD. falls; helping16.In 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.ifB.thatC.thoseD.them18、We will go hiking if it tomorrow.A.will be fineB.is fineC.be fineD. is gong to be fine19、Maybe you if you make some bad friends.A.go wrongB. will go wrongC.going wrongD. is going to be wrong20、—Do you know if finished the work?—Not yet. If he , he will give me a call.A. he’s, will finishB. he’ll, finishesC. he’s , finishesD. he’ll , will finish。