高中名词性从句知识点.doc

优你课教育名词从句名词从句分为主语从句、表语从句、宾语从句、同位语从句。以此举例：It is clear that he has gone.The question is when I can leave.I dont know who he is.The news that he will come late upsets all of us.一、主语从句优你课教育1、由连词that, whether引导的主语从句It is certain that he will come.Whether he will come is doubtful.注：whether引导主语从句，不能用if代替由that引导的主语从句还能改写成由it做形式主语的从句：It is true that the earth is round.这类结构一般有：优你课教育It +be +形容词+that，这类形容词有clear, obvious, likely, true, probable, possibleIt +be + said/believed/reported/hoped/announced/known thatIt +seems/happens/appears thatIt +be +名词+ that从句It is accepted belief that wind is air in movement.普遍认为风是流动的空气2、由连接代词（who，which）和连接副词（when，where，how，why）引导的主语从句，也可以用it做形式主语引导Who let out the news remained unknown. =It remained unknown who let out the news.3、由关系代词what, whatever, whoever等引导的主语从句，此类主语从句不能用形式主语it引导，合成词在句子中担任成分What he said at the meeting is important.主语从句The thing that he said at the meeting is important.定语从句what =the thing that, whoever=any one who, whichever= anything that,但是等号后面的不能引导名词性从句优你课教育（误）No matter who gives us help is welcome.（正）Whoever gives us help is welcome.（误）Ill believe no matter what he says.（正）Ill believe whatever he says.二、表语从句用于表语从句的连词有that, whether, what, whatever, who, whoever, when, where, why, how等优你课教育例：The question is how we can get there.1、that引导的表语从句名词主语+ be+ that 从句常用作主语的名词表示事实、真理或看法、观点：fact, truth, idea, opinion, belief, view, feeling, suggestion, planwh-引导的主语从句+ be+ that从句What surprised me most was that all the pupils were unusually quiet.2、wh-疑问词引导的表语从句This/That +be+ wh- 疑问词引导的从句This is how you make the Italian pizza.名词主语+ be+wh-疑问词引导的从句优你课教育The problem is how scientists can keep in touch with the divers under the sea.注：if不能用来引导表语从句优你课教育3、as if/as though, because引导的表语从句1）as if/as though可以用陈述语气，也可以用虚拟语气It looks as if it is going to rain.The patient looked as if he had been ill for a long time.2）because引导表语从句，主句主语不能用reason（reason与because不见面）It may be because I didnt have a good sleep last night.The reason why she called me is that she will not attend the party.如果主句主语是reason，表语从句连接词用that三、宾语从句1、连词与主语从句和表语从句一样，但是它与主语从句、表语从句的区别是：if可以用于宾语从句中，有时可以和whether互换that在宾语从句中可以省略，主语从句和表语从句中不能省略，that引导的宾语从句常用形式宾语it来引导优你课教育2、介词宾语从句1）that引导的从句做介词宾语从句优你课教育that引导的从句很少做介词的宾语从句，只在except, in, but, besides等少数介词后使用（in that因为，except that除了，but that要不是，除了）I could say nothing but that I was sorry.但可跟在带有形式宾语it之后作介词的真正宾语，这类词有see to负责，depend on依靠，rely on依靠，count on指望例：See to it that the door is safely locked before you go.你走之前一定要锁好门2）关系代词/副词引导的从句做介词宾语从句He was satisfied with what I did.What we should take with us depend on where well stay.3）不及物动词后跟介词宾语从句有些不及物动词后边如果跟宾语从句，省去介词例：I dont care whether he likes me or not. 比较：I dont care about him.I insist that you should learn a second language.比较：I insist on your learning a second language.3、宾语从句中需要注意的事项1）宾语从句时态优你课教育当主句是现在的时态（一般现在时，现在进行时，现在完成时），从句时态可根据实际情况而定。当主句是过去的时态（一般过去时，过去进行时），从句的时态要变为相应过去的时态2）主句是I dont think宾语从句主语必须是第一人称I/we，才能用这样的句型（否定主句，不否定从句）类似I dont think句型的有：I dont imagine, I dont believe, I dont suppose注意该句型反意疑问句用法：I dont think you can do that, can you?3）连词that省略优你课教育对于连接词and或but所连接的两个做宾语的that从句中，第一个宾语从句中的that可以省略，第二个则不能省略He said (that) he has worked for nearly ten years here and that he wanted to go home.4）doubt/sure引导的宾语从句，用whether/if和that的区别句型：I doubt whether/if我怀疑是否；I dont doubt that我毫不怀疑I doubt whether he can speak English. 对比：I dont doubt that he can speak English.句型：Im not sure whether/if我不确定是否；Im sure that我相信Im not sure whether/if the news is true. 对比：Im sure that he can do it well.有两种句型： be+形容词+that从句We are certain that we will do well in English writing. be+ not+形容词+wh-从句He is not sure why so many girls want to be air hostesses.此类形容词有：certain, afraid, sure, anxious, worried, surprised, happy, disappointed.四、同位语从句与先行词同位或同等的从句称为同位语从句，一般由连词that引导，在从句中不担任成分，不能省略，whether也能引导同位语从句同位语从句一般有两种：1、名词+ that引导的从句。常用的同位名词有：answer, belief, doubt, fact, hope, idea, news, order, question, reply, rumo(u)r, thought等例：The rumor that therell be the earthquake soon spread all over the area.2、名词+ wh-疑问词/how引导的同位语从句Have you any idea where they are having a rehearsal?注：同位语从句与定语从句的区别同位语that起连接作用，不充当从句的任何成分，定语从句的关系代词充当从句的某一成分。对比：I believed the fact that he was honest.I believed the fact that he thought to be true.五、名词从句中注意的事项1、连词that用法总结优你课教育that引导主语从句、宾语从句通常用it做形式主语或形式宾语；that在引导宾语从句时可以省略，引导其他从句不能省略2、总结whether和if引导名词从句优你课教育whether可以用于所有的名词从句，if只用于宾语从句1、在宾语从句中，whether后面可直接跟or not，而if不能I dont know whether/if I can come or not.比较：I dont know whether or not I can come.2、如果宾语从句是否定结构，只能用if，而不能用whetherI dont care if he doesnt show up. 优你课教育3、介词宾语从句只能用whether引导We worried about whether he was in good health.4、引导主语从句、表语从句、同位语从句时用whetherThe question whether he should come himself or send another one hasnt been decided.5、whet