主语从句讲解及其练习.doc

名词性从句讲义在复合句中起名词作用的从句叫做名词性从句。它包括主语从句、宾语从句、表语从句和同位语从句。名词性从句是中学阶段的一个重要语法项目，在历年的高考中几乎都涉及到，并且每年的命题各有变化。分析历届高考试题名词性从句考查的焦点主要有以下六个方面1. 考查名词性从句的语序问题2. 考查引导词that与what的区别3. 考查it在名词性从句中作形式主语或形式宾语的用法4. 考查whether与if的区别5. 考查名词性从句中的疑问词+ever引导的名词性从句与no matter+疑问词引导的状语从句的区别6. 考查名词性从句的虚拟语气问题语法要点剖析一、名词性从句主语从句、表语从句、宾语从句、同位语从句，在整个句子中所起的作用，相当于一个名词因此，这四种从句通称为名词性从句。引导名词性从句的连接词可分为三类：连接词：that, whether, if （不充当从句的任何成分）连接代词：what, whatever, who, whoever, whom, whose, which.连接副词：when, where, how, why连接代词和连接副词在句子中既保留疑问意义，又充当句子成分。主语从句主语从句知识点：主语从句的连接词主语从句，it做形式主语（细化：it做形式主语和it做强调句的区别）主语从句的时态（主语从句的时态不受主句时态影响和控制）其他：如，主语从句是陈述句 ；what和tha在引导主语从句的区别；that是否可以省略的问题一、主语从句的连词分三类（1）从属连词引导的主语从句 （that whether /if）that引导的主语从句:引导词that无含义/在句中不做成分/不可以省。That 引导主语从句通常用it 作形式主语。例如：That you will win the medal seems unlikely. That she survived the accident is a miracle.whether 引导的主语从句: whether有含义(是否)/在句中不做成分/不可以省。注意：引导主语从句，不能用if不能在开头，只能用whether。Whether we will hold a party in the open air tomorrow depends on the weather. Whether she is coming or not doesnt matter too much.（2） 用连接代词引导的主语从句 在由连接代词who, whose, whom, which, what, whoever, whomever, whichever, whatever引导的名词性从句中，其连接代词在句中起名词性作用，担当一定成分.例如：What you need is more practice. Whatever we do is to serve the people.注：whatever / whoever的功用whatever, whoever在主语从句中不含疑问意义。它引导主语从句，并在从句中作主语、宾语、表语等。whatever = anything that; whoever = anyone who。要注意和whatever, whoever引导的让步状语从句的区别。如：Whoever breaks the law should be punished. （主语从句）（ Anyone who breaks the law should be punished. ） Whoever breaks the law, he should be punished. （让步状语从句）（ No matter who breaks the law, he should be punished. ）（3）用连接副词when, where, why, how引导的名词性从句(其连接副词有含义,在句中作状语。)例如:Where we should leave it is a problem. When they will come hasnt been made pubic.二、it 作形式主语的主语从句有时为了考虑句子平衡，通常在主语从句处使用形式主语it，而将真正的主语从句移至句末。这分四种情况：(1) 对于以连词that引导的主语从句，通常用形式主语it替代主语从句： It is +名词+从句It is a fact that 事实是；It is good news that 是好消息；It is a question that 是个问题；It is common knowledge that 是常识类似的名词还有：a pity；a wonder；a good thing； no wonder； surprise等。It is a mystery to me how it all happened.It is common knowledge that the whale is not a fish.It is no surprise that Bob should have won the game. It is +形容词+从句It is necessary that 有必要；It is clear that 很清楚；It is likely that 很可能；It is important that 重要的是类似的形容词还有：strange; natural; obvious; true; good; wonderful; possible; unlikely; quite; unusual; certain; evident; worth-while; surprising; interesting; astonishing, etc.It is doubtful whether she will be able to come.It is essential that he should be here by the weekend.It seems obvious that we can not go on like this.It is necessary that you （should）master the computer. 需要注意的是这类主语从句中，谓语动词很多为“（should）动词原形”，即要用虚拟语气。另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, natural, strange, etc.) that It is a pity (a shame, no wonder, etc.) that It is suggested (requested, proposed, desired, etc.) that It is +过去分词+从句It is said that 据说；It is reported that 据报道；It has been proved that 已证明；It must be proved that 必须指出类似的过去分词还有：known; estimated; expected; believed; thought; hoped; noted; discussed; required; decided; suggested; demanded; made clear; found out,etc.例如：It is used to be thought that a new star must be due to a collision between two stars. It has not been made clear when the new road is to be opened to traffic. It seems不及物动词（happened / appears / doesntt matter / makes no difference / occurred ）that 主语从句不可提前 It makes no difference whether he will attend the meeting or not. It does not matter if I missed my train.It happened that I saw him yesterday. (2) 对于以连接代词(副词)引导的主语从句，可以使用形式主语代主语从句，也可直接在句首使用主语从句：Whether they would support us was a problem. 他们是否会支持我们还是一个问题。It was a problem whether they would support us.他们是否会支持我们还是一个问题。(3) 对关系代词型what引导的主语从句，通常直接将主语从句放在句首。如：What we need is money. 我们需要的是钱。What I want to know is this. 我想知道的就是这一点。有时也可将助用形式主语。如：It is clear enough what he meant. 他是什么意思很清楚。(4) 如果句子是疑问句，则必须用带形式主语it的结构：Is it true that he is the girls father? 他是那女孩的父亲，是真的吗？How is it that you are late again? 你怎么又迟到了？三、主语从句的时态，从句时态不受主句时态的影响和控制 （1）That he finished writing the composition in such a short time surprised us all. （2）Whether we will go for an outing tomorrow remains unknown. （3）Who will be our monitor hasnt been decided yet. （4） Whom we must study for is a question of great importance. （5）What caused the accident remains unknown. （6）Whatever you did is right. （7）Whose watch was lost is unknown. （8）What we need is time. （9）What we need are good doctors. 小结: 连词位于句首不能省略 主语从句大多数情况下视为三单,但也有例外,如例9四、主语从句其他知识点（一）连词that的省略问题引导主语从句的连词that 有时可省，有时不能省，其原则是：若that引导的主语从句直接位于句首，则that不能省略；若that引导的主语从句位于句末，而在句首使用了形式主语it，则that可以省略：That you didnt go to the talk was a pity. 很遗憾你没去听报告。(that不可省)It was a pity (that) you didnt go to the talk. 很遗憾你没去听报告。(that可省)（二）what 与that 在引导主语从句时的区别what 引导主语从句时在从句中充当句子成分，如主语、宾语、表语，而that 则不然。 What you said yesterday is right.That she is still alive is a consolation.（三）whethwe和if引导名词性从句区别whether与if 均为是否的意思。 但在下列情况下，只可用whether1. whether引导主语从句并在句首。 eg:Whether he can come to the party on time depends on the traffic。2. 引导表语从句。 eg:The question is whether we can get in touch with her.3. whether从句作介词宾语。 eg:I am thinking about whether I should quit my present job. 4. if与whether都可以与or not 连用，但后面紧跟or not 时只能用whether。 We didnt know whether or not she was ready.（此时只能用whether） 5. Whether可以引导同位语从句，if不引导同位语从句。5、 高考题：1、It never occurred to me_you could succeed in persuading him to change his mind.(陕西高考)Awhich Bwhat Cthat Dif2、Its obvious to the students_they should get well prepared for their future.(天津卷)Aas Bthat Cwhich Dwhether3、_some people regard as a drawback is seen as a plug by many others.(2010北京)AWhetherBWhat CThat DHow主语从句练习题1._ makes mistakes must correct them.A. What B. That C. Whoever D. Whatever2. It worried her a bit _ her hair was turning grey.A. while B. that C. if D. for 3.When and why he came here _ yet.A. is not known B. are not known C. has not known D. have not known4. _ is no reason for dismissing her.A. Because she was a few minutes late B. Owing to a few minutes lateC. The fact that she was a few minutes late D. Being a few minutes late5. _ Tom liked to eat was different from _.A. Thatthat you had expected B. What that you had expectedC. Thatwhat you had expected D. Whatwhat you had expected6._ we go swimming every day _ us a lot of good.A. If.do B. That.do C. If.does D. That.does7.It _ Bob drives badly.A. thinks that B. is thought what C. thought that D. is thought that8.Its uncertain _ the experiment is worth doing.A. what B. that C. whether D. how9._ the boy didnt take medicine made his mother angry.A. That B. What C. How D. Which10._ we cant get seems better than _ we have.A. What, what B. What, that C. That, that D. That, what11._ you dont like him is none of my business. A. What B. Who C. That D. Whether12