1、九年级英语上册第六单元知识点讲解TV programsGrammar重点短语1 be in danger处于危险状态 e.g. The country was in danger. 那个国家处于危险之中。2 have a chance to do sth.有机会去做某事 e.g. I hope that Ill have a chance to go skating there.我希望以后有机会去那儿溜冰。语法纵横状语从句( III)一、if引导的条件状语从句1.定义及用法 条件状语从句在复合句中表示主句动作发生的条件。条件状语从句最常用的引导词是if,意为“如果，假如”,表示在某种条件下某事
2、很可能发生。 e.g. If you ask him, he will help you.如果你请他帮忙,他会帮你的。 The cat will scratch you if you pull her tail. 如果你拉猫的尾巴,它就会抓你。注意:if引导的条件状语从句可以位于主句之前，也可位于主句之后。如果从句在前，从句与主句之间要用逗号隔开。2. if引导的条件状语从句的时态(1)若if引导的条件状语从句表示将来可能发生的事情,主句常用一般将来时,从句用一般现在时;若if引导的条件状语从句是表示与现在事实相反的情况，主句用一般过去时,从句也要用表示过去的相应时态。 e.g. If you
3、 leave now ,you will be regretful.如果你现在离开,你会后悔的。 If I didnt apologize ,I would feel guilty.如果我不道歉，我会感到内疚。(事实:道歉了)注意:在条件状语从句中，主句只能用will或shall表示一般将来时，而不能用be going to。(2)在含有if引导的条件状语从句的复合句中,主句也可含有情态动词或者是一个祈使句,从句用一般现在时。 e.g. If it stops snowing, we can go out.如果雪停了，我们就可以出去。 Dont wait for me if Im late.如
4、果我迟到了,不要等我。二、unless引导的条件状语从句1.定义及用法 条件状语从句也可由unless 来引导,它的意思是“除非,如果不 ,表示某件事只在特定情形下才会发生或成立。 e.gUnless you study hard ,you will never pass the exam.除非你刻苦学习，否则考试永远不能及格。 You will be late unless you go at once.如果你不马上走,你就会迟到。2. unless引导的条件状语从句的时态(1)在含有unless引导的条件状语从句的复合句中,主句常用一般将来时,从句用一般现在时。e.gUnless it r
5、ains , the game will be played on schedule.如果不下雨, 比赛将照常进行。(2)在含有unless引导的条件状语从句的复合句中，主句也可以含有情态动词或者是一个祈使句，从句用一般现在时。e.g. He cannot see clearly unless he wears glasses.他不戴眼镜就看不清楚。Dont make any promise unless you can keep it. 不要轻易许诺，除非你能兑现。3. unless与if.not的区别(1)if.not与unless一样,也表示“除. ,如果不. ,在很多情况下,二者可以互
6、换使用。e.g. I wont go to the party unless Im invited. = I wont go to the party if Im not invited. 如果不被邀请,我不会去参加晚会的。(2)当某种条件所引起的结果是一种情绪或想法时,只能用if.not,不用unless。e.g. I will be happy if I dont have to do the homework. (V )I will be happy unless I have to do the homework.( x)(3)当引导虚拟条件句、表示与现在事实相反的情况时，只能用if.
7、not,不用unless。e.g. If you werent always in such a hurry , your work would be much better. (V)Your work would be much better unless you were always in a hurry.( x )课后实践运用高效练习场语法专练I.用所给单词的正确形式填空。1. If you (feel) tired ,you can have a rest.2. Where he ( see) the film if he (have) time?3. If I ( have) en
8、ough money next year, I (go) to England.4. Im sure that he_( come) unless he (be) ill,5. You ( fail) unless you ( work) harder.II.单项选择。( )1. If there no buying and selling of animals , there no killing in nature.A. is; will be B. will be ; will beC. is; is D. will be ; is( )2. The students have a sp
9、orts meeting this weekend if it A. wont; rains B. will ;rainsC. wont; will rain D. are not going to; rains( )3.1 dont know if he ,If he please let me know.A. comes ; comes B. comes ; will comeC. will come ; comes D. will come; will come( )4. Im waiting for my friend ,Ill go shopping alone. A. If she comes B. If she doesnt come C. If she wont come D. Unless she doesnt come( )5. She wont sing a song she is asked. A. if B. unless C. for D. since
