高三英语一轮之名词性从句.ppt

1、在英语的句子结构中，如果本该由名词充当的主语、宾语、表语和同位语，由一个句子来充当，那么这个句子就叫_。主语从句宾语从句表语从句同位语从句名词性从句名词性从句引导词连接词：that,whether,if,because，as if,as though连接代词:who,whom,what,which,whose，whatever连接副词:when,where,why,how，however,wherever名词性从句的引导词充当：主宾表定充当：状语不充当成份1.What I want to do is to go shopping.2.She had a feeling that she was

2、 being watched.3.I dont think that he is an honest boy.4.Who will go with you is decided by yourself.(主语从句)(同位语从句)(宾语从句)(主语从句)判断从句的方法：一 找谓语动词二 找引导词划从句三 看从句在主句的位置请判断出下列的句子属于哪种从句：在名词性从句中一律用陈述句的语序，即使从句表达的是疑问含义。The problem is what he has done to the little boy.问题是他对那个小男孩做了些什么。1.主语从句在句中作主语的句子叫主语从句。主语从句通常

3、由从属连词that，whether 和连接代词what,who,which,whatever,whoever以及连接副词how,when,where,why等词引导。that在从句中无词义，只起连接作用；连接代词和连接副词在句中既保留自己的疑问含义、又起连接作用，在从句中充当成分。Who will win the match is still unknown.Where the English evening will be held has not yet been announced.That he stole a bike was true.What he wants to tell u

4、s is not clear.单个的主语从句作主语时，谓语动词用单数形式。如果是两个或两个以上的主语从句作主语，谓语动词则用复数形式。Where and when he was born has not been found.When the person was murdered and why he was murdered are still unknown.有时为避免句子头重脚轻，常用it 代替主语从句作形式主语放于句首，而把主语从句置于句末。主句的谓语动词一般用单数形式。常用句型如下：1）It+be+名词+that从句2）It+be+形容词+that从句3）It+be+动词的过去分词

5、+that从句4）It+不及物动词+that 从句It is known to us how he became a writer.注意:在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时，谓语动词要用虚拟语气“(should)+do”，常用的句型有：It is necessary/important/naturalstrange,etc.)that 2.宾语从句名词句用作宾语的从句叫宾语从句。引导宾语从句的关联词与引导主语从句表语从句的关联词大致一样，在句中可以作及物动词或介词及某些形容词的宾语。连接词that引导宾语从句时，句中不担任任何成分，在口语或非正式的文体中常被省去。但下面情

6、况中不能省略。（1）that一般不能充当介词宾语,但except,in的宾语。如:He is a good student except that he is a little bit careless.他是个好学生,就是有点粗心。He differed from his classmates in that he devoted his spare time to reading.他和他的同学不同的地方在于他把课余时间用在了读书上。其他介词后面需要用that从句作宾语时,必须用it作形式宾语。如:You may depend on it that I shall always help yo

7、u.你要相信我会一直帮助你的。1.由连接词that引导的宾语从句注意:在demand,order,suggest,advise,decide,insist,desire,request,command等表示要求、命令、建议、决定等意义的动词后，宾语从句常用“should+动词原形”。should可省略I insist that she(should)do her work alone.The commander ordered that troops(should)set off at once.但是,如果suggest作“表明、暗示”讲,insist作“坚持说、坚持认为”讲，则其后的宾语从句

8、中应该用陈述语气。The smile on his face suggested that he had passed the examination.连接词 whether 和if表“是否”,引导名词性从句时在从句中不担当句子成分,但有自己的意义。在下列情况下只能用whether而不用if:(1)在主语从句、表语从句和同位语从句中;(2)在介词后的宾语从句中;(3)与or not连在一起使用时。(4)discuss后必须用whether引导宾语从句。(5)跟不定式连在一起使用时典例4(2013陕西,20)It remains to be seenthe newly formed commit

9、tees policy can be put into practice.答案 whether2.whether/if的用法4)宾语从句中的时态呼应宾语从句的谓语动词时态受主句谓语动词的影响，如果主句的谓语动词是一般现在时从句中的谓语动词可以用各种时态；I know that he studies English every day.I know(that)he will study English next year.We all know that he has studied English since 1998.I know that he studied English last t

10、erm.The teacher told us that Tom had left us for America如果主句中的谓语动词用了一般过去时，则从句中的语动只能用过去时的某种形式，如一般过去时，过去进行时，过去将来时等；We believed that he had earned enough money to build a house.The teacher told us that Tom had left us for America当从句表示的是客观真理，科学原理，自然现象，则从句仍用现在时态。The teacher told us that the sun rises in

11、the east.5)当主句是I/We think(suppose,expect,believe,guess,imagine)时，其后的宾语从句如果是否定形式，常把否定词not从从句中转移到主句中成为否定的转移。We dont believe that he will win the game.I dont think he will do so.doubt用于肯定结构时，后面用whether/if 引导名词性从句；用于否定结构或疑问结构时，后面用 that 引导名词性从句。be sure 用于肯定句或疑问句时，后接 that 引导的名词性从句；用于否定句时，后接whether/if 引导的名

12、词性从句。连接代词whoever，whatever，whichever可引导名词性从句，相当于anyone who,anything that等。它们也可以引导让步状语从句，相当于 no matter who/what/which。Whoever breaks the law should be punished.3.表语从句在句中作表语的句子叫表语从句。引导表语从句的关联词与引导主语从句的关联词大致一样，表语从句位于连系动词后，有时用as if,because 引导。其基本结构为：主语+系动词+that从句The fact is that we have lost the game.That

13、s just what I want.This is where our problem lies.That is why he didnt come to the meeting.It looks as if it is going to rain.This is because he missed the train by one minute.在句中用作同位语的从句叫做同位语从句。同位语从句一般放在如idea,news,fact,promise,suggestion,belief,truth等含有丰富内涵的抽象名词后面，用来说明前面那个词的具体内容。引导同位语从句的连接词通常有that,

14、whether和连接副词when,where,why,how；连接代词who，what，whose，which通常不引导同位语从句。1.He gave her a promise that he would come back after two months.2.She had a feeling that she was being watched.3.The news that he couldnt come makes us upset.4.Whatever gave you the idea that I can sing?5.I have no idea whether/when/how he will come.4.同位语从句同位语从句和定语从句的区别：that作为关系代词，可以引导定语从句，充当句子成分，在从句中作宾语时可以省略；that引导同位语从句时，起连词的作用，没有实际意义，不充当句子成分，一般不能省略。I had no idea that you were here.Have you got the idea（that）this book gives you of life in ancient Greece？(that引导同位语从句,不能省略）(that引导定语从句，作宾语，可以省略）