名词性从句讲解

名词性从句名词性从句的概念概念：起名词作用的从句叫名词从句。它和名词一样，在句中可充当主语，表语，宾语和同位语。名词从句包括主语从句，表语从句，宾语从句和同位语从句。名词从句的引导词通常有：1.连词that,whether,if. 2.连接代词what,whatever,who,whoever,whose,which 3.连接副词when,where,how,why请判断出下列的句子属于哪种从句WhatIwanttodoistakingabath.Thenewsthattheywonthegamespreadthewholeschool.Idon’tthinkheisanhonestboy.Thefactisthathestolethecar.Doyouknowthefactthathestolethecar?Doyouknowthemanwhoisstandingoverthere?Itissaidthattheywonthegame.(主从)(同位语从句)(宾从)(表从)(同位语从句)(定从)(主从)主语从句在句中充当主语的从句叫做主语从句。主语从句可以放句首,但多数放句末.句首用形式主语IT.

Thattheearthisroundistrue.=Itistruethattheearthisround.Whetherhewillcomehasn’tbeendecided.=Ithasn’tbeendecidedwhetherhewillcome.

注意：连词that,whether在从句中不担任句子成分，只起连接作用，不能省略。并且whether引导主语从句时不能用if代替。3.Wholetoutthenewsremainedunknown.4.Howthishappenedisstillaquestion.5.Whyhedidn’tcomehereisnotcleartoanyone.注意：who,which,how,when,where,why在所引导的主语从句中可担任主语，宾语，状语，不能省略。可以用形式主语it引导。

6.Whathesaidatthemeetingisimportant.

7.Whoeverleavestheofficeshouldtellme.

8.WhenevertheOlympicGameswillbeheldinBeijingisnotknownyet.

注意：who,whom,which,what等可以和ever构成合成词，引导主语从句和宾语从句。此类主语从句不能用it引导，引导词在句中担任句子成分，不能省略。另外，有的“It…＋主语从句”已成为固定结构。如：

It+is+形容词＋that从句Itisnecessarythat…有必要…Itisimportantthat….重要的是…Itisobviousthat……很明显……It+is+-ed分词＋that从句Itisbelievedthat…人们相信…Itisknowntous/allthat….众所周知…Ithasbeendecidedthat……已经决定……It+is+名词＋that从句Itiscommonknowledgethat……是常识Itisasurprisethat….令人惊奇的是…Itisafactthat……事实是……It+不及物动词＋that从句Itappearsthat…似乎…Ithappensthat….碰巧…Itoccurredtomethat……我突然想起……表语从句在句中充当表语的从句(多数放在be动词后面)叫做表语从句。That’swhatweshoulddo.

Ourpurposeisthathecanrealizehisfaults.注意：引导表语从句的连接词一般不省略。That’swhyIwanttoseeyou.Thequestioniswhetheritisworthdoing注意：表语从句表示“是否”只用“whether”而不用“if”

1.be,seem,look等动词后均可跟表语从句：Mysuggestionisthatweshouldgoshopping.

Itseemsthatitisgoingtorain.

2.asif,because也可引导表语从句。Itlooksasifit’sgoingtorain.

ItwasbecauseIgotuplate.

注意：在表语从句中，当reason作主语时，引导词只能用that，不能用because，如：

Thereasonwhyhewaslatewasthathedidn’tcatchtheearlybus.试区分以下句子Isthismuseumwhatyouvisited?Isthisthemuseumthatyouvisited?Isthismuseumtheonethatyouvisited?注意：这种句子考试时一定要记住这句话：名词前（尤其是单数可数名词前）一定要有限定词。然后把句子变换成陈述句，接着判断句子是属于哪种从句再完成。(表从)(定从)(定从)宾语从句在复合句中充当宾语的句子叫做宾语从句。1.作动词宾语Idon’tknow（that）youwillcomehere.Iwonderwhathehasdone.2.作介词宾语TheteacherissatisfiedwithwhatIsaid.Heisthinkingabouthowtosolvetheproblem.3.作afraid,glad,certain,sure等形容词的宾语IamafraidthatIwillbelateIamgladyoupassedtheexam.我不知道他来不来。我想知道他来还是不来。你们是在谈论着他来还是不来吗？他不在乎天气是否好。Idon’tknowwhether/ifhewillcome.Iwanttoknowwhetherhewillcomeornot.Areyoutalkingaboutwhetherhewillcome?Hedoesn’tcareifitisn’tafineday.注意：在宾语从句中，表示“是否”既可以用whether,也可以用if.但是，whether常与ornot连用；作介词宾语只用whether;从句是否定句时一般用if。宾语从句中的否定转移我认为他不会来这里Ithinkhewon’tcomehere.()Idon’tthinkhewillcomehere.()Ibelievehewon’tseeyou.Idon’tbelievehewillseeyou.注意：如果宾语从句是由think,believe,imagine,suppose,expect等词引导的时候，要将从句中的否定形式转移到主句中去。宾语从句中用it作形式宾语Wethinkitourdutythatweshouldhelpothers.Ifinditimpossiblethatheshouldfinishtheworkintwodays.Iconsideritnecessarythatheshoulddoitagain.注意：如果主句中有形容词或名词作宾语补足语时，一般用it来作形式宾语，把从句放在宾补后面。Iinsistedthathe（should）doitatonce.

Shesuggestedthatthework（should）befinishedatonce.

IThemayororderedthatthebridge(should)berepairedassoonaspossbile.注意：在suggest,insist,demand,order,require等表示建议，命令，要求的动词后，从句的谓语动词要用虚拟语气。如：同位语从句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,hope,thought,doubt,truth等含有丰富内涵的词语后面，用来说明前面那个词的具体内容。一般说来，同位语从句都用that来作连接词，而且不能省略。也可用how,when,where等。他给了她一个承诺，他会在两个月后回来。Hegaveherapromisethathewouldcomebackaftertwomonths.SomemoreexamplesTherumourthattherewillbeanearthquakesoonspreadalloverthearea.2.Theyhavenohopethathewillrecover.3.Ihavenoideawheretheyhavegone.同位语从句与先行名词有时也可以分开:4.Suddenlythethoughtcametomethathecouldgoblind.同位语从句与定语从句的区别：（1）同位语从句的先行名词极为有限，而定语从句的先行词则不计其数。（2）引导同位语从句的连词that在句中不担任句子成分，而引导定语从句的that则在从句中作主语，宾语等。（3）同位语从句与先行名词是等同关系，一个具体，一个抽象，两者常可以转述为主表关系，而定语从句与先行词是修饰与被修饰关系。（４）如果是定语从句，它的从句肯定是不完整的，关系词肯定在句中充当成分的；而同位语从句中的that只起连接作用。（５）定语从句是对先行