if引导的条件状语从句.doc

. 语法 10单元语法 再现 梁老师组稿 2017-12-31一、观察下面的句子If you go to the party, you will have a great time.If you do , you will be late.If you do, you will be sorry.If they have it today, half the class wont come.If we ask people to bring food, they will just bring potato chips and chocolate.以上几个句子中“if”有相同的含义“如果”，引导条件状语从句逗号后面的句子是主句。整个连起来的大句子叫主从复合句。注意主句和从句的时态有什么特点。总结：If引导的条件状语从句用一般现在时，主句用一般将来时。简称“主将从现”练习：（1）If you _(come)here, you _(be) happy.(2) If it _(rain) tomorrow, we_(not, go) to the park.(3) If he _(come) here, I _(call) you.(4) If it _(not rain), we _(have) a picnic(野餐).(5) If we do that, more people _(want) to play the games.(6) If they _ that , the games _(be) more exciting, too.(7)What _ happen if they_ (have) the party today?(8) What _ happen if they _ a video at the party?(9) If he _(take) a taxi, it _(be) too expensive.(10) If I _(go) to the movies, I _(finish) my homework.条件状语从句的引导词还有“unless 除非（否则），如果不”You wont pass the exam unless you study hard.Unless you deal with(处理）your problems, you will be unhappy.二、同样when可以引导状语从句“主将从现”也适合也就是说：when引导的时间状语从句也是一般现在时，主句也是一般将来时。What are you going to be when you grow up?What is he going to be when he grows up?三、“主将从现”的含义扩充主： 表示主句将： （1）主句是 一般将来时（2）主句是祈使句（3） 主句含有情态动词can、may、must/have to从： 表示状语从句现： 表示状语从句是一般现在时例句：(1)Dont go and play football if your homework _(not finish) .(2)If it _(not rain) tomorrow, we _(go)to climb the hill.(3)He wont leave until you _(agree)with him.(4) You can cross the road when the lights _(turn) green.(5)I _(call)you as soon as he _(tell) me about the good news.(6)The students will go to Summer Palace if it _ tomorrow. A. dont rain B.wont rain C. doesnt rain D. isnt rain四、if 翻译成“是否”，引导宾语从句， 时态是：一般将来时。例如： I dont know if he will come tomorrow.V.He asks me if I will be free .V.They want to know if they will have a party next week.V.注意把if的两个意思放在一道题中考试。 （主将 从现 宾将）Mary wants to know if Tom will come. If he comes, I will call Mary.练习： 1.I dont know if it _ tomorrow. If it _ , well go out for a picnic.A. will rain; doesnt rain B. will rain; rains C. rains ; will rain2.-Does Ted tell you if he _next Sunday?-No, he doesnt. But if he _. Ill give you a ring.A. will come; will come B. comes; will come C. comes ; comes D. will come; comes3. -I wonder if it _tomorrow.-Dont worry. If it _, well stay at home.A. rains; rains B. will rain; rains C. rains; will rain5、 含有时间状语从句的主从复合句，常考时态有两种可能：常考的引导词when 、 as soon as(一-就-）、 not- until-（直到-才-）主句 从句1、 主将从现（1） He is going to be an engineer when he grows up. 主句：一般将来时 when 引导的时间状语从句一般现在时（2） I will call you as soon as he comes here. 主句：一般将来时 as soon as引导的时间状语从句一般现在时(3) I wont go to bed until I finish my