1、名词性从句用法归纳名词性从句:在句子中起名词作用的句子叫名词性从句(NounClauses)。名词性从句在复合句中能担任:主语、宾语、表语、同位语、介词宾语等。名词性从句分为:主语从句、宾语从句、表语从句和同位语从句。一、引导名词性从句的连接词引导名词性从句的连接词可分为三类:1、从属连词(5个):(1)that无词义,在从句中不做成分,在宾语从句或表语从句中that有时可以省略(2)whether,if有词义,在从句中不做成分(whether,if均表示“是否”之意,表明从句内容的不确定性)不可以省略(3)asif,asthough(均表示“好像”,“似乎”之意)在从句中不做成分2、连接代词
2、(9个):what,whatever,who,whoever,whom,whomever,whose,which,whichever,有词义,在从句中做成分,不可以省略(whowhatwhich在从句中做主语、宾语、其中what指代没有范围的事物,which指代有范围的事物,表“选择哪一个”whom做宾语whose做定语)3、连接副词(7个):when,where,how,why,whenever,wherever,however有词义,在从句中做状语,不可以省略4、that省略的情况:(1)定语从句中做宾语(2)that引导宾语从句时(3)that引导表语从句时(4)主语从句中it做形式主语
3、,that从句置于句末时5、that不可省略的情况:(1)定语从句中做主语(2)由that引导主语从句放句首时(3)that引导同位语从句时(4)宾语从句中iit做形式宾语,真正的that宾语从句中that不可以省略ii一个句子有两个或多个并列的宾语从句时,引导第二个和以后几个句子中的that不可以省略iii与动词相隔的宾语从句,不可以省略ivthat引导的宾语从句放在句首时,不可以省略二.主语从句1、主语从句:作句子主语的从句叫主语从句。主语从句通常由下列词引导:1)从属连词that,whether等;2)连接代词what,who,which,whatever,whoever,whom等;3
4、)连接副词how,when,where,why等。2、that在句中无词义,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,在从句中充当从句的成分。注:whom、who指人,what指物,whatever,whoever表示泛指意义。例如:Whathewantstotellusisnotclear.Whowillwinthematchisstillunknown.Itisknowntoushowhebecameawriter.WheretheEnglisheveningwillbeheldhasnotyetbeenannounced.注意:有时为避免句子头重脚轻,常用
5、形式主语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。主语从句后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:Itisafactthat事实是Itisanhonourthat非常荣幸Itiscommonknowledgethat是常识Itisapitythat遗憾(2)It+be+动词的过去分词+that从句:Itissaidthat据说Itisreportedthat据报道Ithasbeenprovedthat已经证明Itisbelievedthat人们认为Itissupposedthat据猜测(3)It+不及物动词(vi)+that从句:Itse
6、emsthat似乎Ithappenedthat碰巧Itappearsthat似乎(4)It+be+形容词+that从句Itisnaturalthat很自然Itisstrangethat奇怪的是注意: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:Itisnecessary(important,natural,strange,etc.)thatItissuggested(requested,proposed,desired,etc.)that3、It作形式主语和it引导强调句的比较It作形式主语代替主语从句,主要是为了平衡句
7、子结构,主语从句的连接词没有变化。it引导的强调句则是对句子某一部分进行强调,无论强调的是什么成分,都可用连词that引导,被强调部分指人时也可用who/whom。例如:a)Itisapitythatyoudidntgotoseethefilm.b)Itdoesntinterestmewhetheryousucceedornot.c)Itisinthemorningthatthemurdertookplace.(强调句型)d)ItisJohnthatbrokethewindow.(强调句型)4、注意:since,if不能引导主语从句,但当it做形式主语,主语从句放在句末时,if,whether
8、均可5、主语从句不可位于句首的五种情况:(1)if引导的主语从句不可居于复合句句首。(2)Itissaid/reported结构中的主语从句不可提前。例如:正确表达:ItissaidthatPresidentJiangwillvisitourschoolnextweek.错误表达:ThatPresidentJiangwillvisitourschoolnextweekissaid.(3)Ithappens/occurs结构中的主语从句不可提前。例如:正确表达:Itoccurredtohimthathefailedintheexamination.错误表达:Thathefailedintheex
9、aminationoccurredtohim.(4)Itdoesntmatterhow/whether结构中的主语从句不可提前。例如:正确表达:Itdoesntmatterwhetherheiswrongornot.错误表达:Whetherheiswrongornotdoesntmatter.(5)含主语从句的复合句是疑问句时,主语从句不可提前。例如:正确表达:Isitlikelythatitwillrainintheevening?错误表达:Isthatwillrainintheeveninglikely?6、what与that在引导主语从句时的区别what引导主语从句时在句时在从句中充当句
10、子成分,如主语宾语表语,而that则不然。例如:a)Whatyousaidyesterdayisright.b)Thatsheisstillaliveisaconsolation三、表语从句表语从句:在复合句中,位于系动词之后作表语的从句叫表语从句。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asif引导。可以接表语从句的系动词有be,look,remain(保持),seem等常用的还有thereasonisthatItisbecauseItappears/seemsthatIthappensthatItturnsoutthat(结果是.)等结构由从属连词
11、,连接代词,连接副词引导,其中that常常可以省略由asif,asthough引导ItlooksasifItseemsasifwhy,because都可以引导表语从句,但why强调结果,because强调理由当主语为suggestion,order,requirement,advice,request,demand等这类名词时,表语从句用虚拟语气(should)doif不能引导表语从句注意:当主语是reason时,表语从句要用that引导而不是because。例如:Thereasonwhyhewaslatewasthathemissedthetrainbyoneminutethismornin
12、g.【注意】whether可引导表语从句,但与之同义的if却通常不用于引导表语从句。四、同位语从句1、同位语从句说明其前面的名词的具体内容。同位语从句通常由that引导,that不可以省略由whether引导,不可用if2、可用于同位语从句的名词有belief、advice、demand、doubt(怀疑)、possibility、though、proposal、case、fact、hope、idea、information、message、news、order、problem、promise、question、request、suggestion、truth、wish、word等。例如:Th
13、enewsthatwewonthegameisexciting.Ihavenoideawhenhewillcomebackhome.ThethoughtcametohimthatMaryhadprobablyfallenill.3、在noidea后用wh-疑问词引导4、同位语从句与定语从句的区别(1)定语从句中的that既代替先行词,同时以在从句中作某个成分(主语或宾语),而同位语从句中的that是连词,只起连接主句与从句的作用,不充当句中任何成分。(2)定语从句是形容词性的,其功能是修饰先行词,对先行词加以限定,描述定的性质或特征;同位语从句是名词性的,其功能是对名词进行补充说明。例如:1)
14、ThenewsthathetoldmeisthatTomwouldgoabroadnextyear.(他告诉我的消息是汤姆明年将出国。)(第一个that引导的从句是定语从句,that在从句中作宾语)2)ThenewsthatTomwouldgoabroadistoldbyhim.(汤姆将出国的消息是他讲的。)(同位语从句,that在句中不作任何成分)五、宾语从句宾语从句:名词从句用作宾语的从句叫宾语从句。由从属连词、连接代词、连接副词引导。1.由连接词that引导的宾语从句由连接词that引导宾语从句时,that在句中不担任任何成分,在口语或非正式的文体中常被省去,但如从句是并列句时,第二个分
15、句前的that不可省。例如:HehastoldmethathewillgotoShanghaitomorrow.Wemustneverthink(that)wearegoodineverythingwhileothersaregoodinnothing.注意:在demand、order(命令)、suggest、decide、insist(坚持),desire,urge,advice,propose,require,request,command(命令),doubt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”。例如:Iinsistthatshe(shou
16、ld)doherworkalone.Thecommanderorderedthattroops(should)setoffatonce.2.用who,whom,which,whose,what,when,where,why,how,whoever,whatever,whichever等关联词引导的宾语从句相当于特殊疑问句,应注意句子语序要用陈述语序。例如:Iwanttoknowwhathehastoldyou.Shealwaysthinksofhowshecanworkwell.Shewillgivewhoeverneedshelpawarmsupport.3.用whether或if引导的宾语
17、从句,其主语和谓语的顺序也不能颠倒,仍保持陈述句语序。此外,whether与if在作“是否”的意思讲时在下列情况下一般只能用whether,不用if:a.引导主语从句并在句首时;b.引导表语从句时;c.引导从句作介词宾语时;d.从句后有“ornot”时;e.后接动词不定式时。例如:Whetherthereislifeonthemoonisaninterestingquestion.Everythingdependsonwhetherwehaveenoughmoney.Iwonderwhetherhewillcomeornot.Canyoutellmewhethertogoortostay?4.
18、注意宾语从句中的时态呼应,当主句动词是现在时,从句根据自身的句子情况,而使用不同时态。例如:Iknow(that)hestudiesEnglisheveryday.(从句用一般现在时)Iknow(that)hestudiedEnglishlastterm.(从句用一般过去时)Iknow(that)hewillstudyEnglishnextyear.(从句用一般将来时)Iknow(that)hehasstudiedEnglishsince1998.(从句用现在完成时)当主句动词是过去时态(could,would除外),从句则要用相应的过去时态,如一般过去时,过去进行时,过去将来时等;当从句表示
19、的是客观真理,科学原理,自然现象,则从句仍用现在时态。例如:TheteachertoldusthatTomhadleftusforAmerica5.think,believe,imagine,suppose,guess,expect,fancy,consider等等动词引起的否定性宾语从句中,要把上述主句中的动词变为否定式。即将从句中的否定形式移到主句中。例如:Wedontthinkyouarehere.我们认为你不在这。Idontbelievehewilldoso.我相信他不会这样做。6、后面不能接that从句的动词有:condemn谴责,判刑force强迫take拿走forgive原谅di
20、slike不喜欢refuse拒绝letlikelovehelpadmire羡慕allowcelebratecause注:以上动词后不能接that从句,但可以用不定式,动名词做宾语。六、whether与if均为是否的意思。但在下列情况下,只可用whether:1.whether引导主语从句并在句首时,只能用whether,当it做形式主语,主语放句首时,whether,if均可eg:whetherhecancometothepartyontimedependsonthetraffic2.引导表语从句eg:Thequestioniswhetherwecangetintouchwithher3.wh
21、ether从句作介词宾语e.g:Itdependsonwhetherhewillcome.4.if与whether都可以与ornot连用,但后面紧跟ornot时只能用whetherWedidntknowwhetherornotshewasready.(此时只能用whether)Iwonderwhether/ifthenewsistrueornot.(此时则二者都可以用)5.引导同位语从句Whetherhewillcomeisnotclear.6.后接不定式时EgIdontknowwhethertogo.7.在discuss后只能用whether注意:(1)大部分连接词引导的主语从句都可以置于句
22、末,用it充当形式主语。Itisnotimportantwhowillgo.Itisstillunknownwhichteamwillwinthematch.(2)whether从句中不能有否定式,而if可以Idontcareifhedoesntcome.七、名词性that-从句(1)由从属连词that引导的从句叫做名词性that-从句。That只起连接主句和从句的作用,在从句中不担任任何成分,本身也没有词义。名词性that-从句在句中能充当主语、宾语、表语、同位语和形容词宾语,例如:主语:Thatsheisstillaliveisherluck.她还活着全靠运气。宾语:Johnsaidtha
23、thewasleavingforLondononWednesday.约翰说他星期三要到伦敦去。表语:Thefactisthathehasnotbeenseenrecently.事实是近来谁也没有见过他。同位语:Thefactthathehasnotbeenseenrecentlydisturbseveryoneinhisoffice.近来谁也没有见过他,这一事实令办公室所有的人不安。形容词宾语:Iamgladthatyouaresatisfiedwithyourjob.2)That-从句作主语通常用it作先行词,而将that-从句置于句末,例如:Itisquiteclearthatthewho
24、leprojectisdoomedtofailure.很清楚,整个计划注定要失败。Itsapitythatyoushouldhavetoleave.你非走不可真是件憾事。用it作形式主语的that-从句有以下四种不同的搭配关系:a.It+be+形容词+that-从句Itisnecessarythat有必要Itisimportantthat重要的是Itisobviousthat很明显b.It+be+-ed分词+that-从句Itisbelievedthat人们相信Itisknowntoallthat众所周知Ithasbeendecidedthat已决定c.It+be+名词+that-从句Itis
25、commonknowledgethat是常识Itisasurprisethat令人惊奇的是Itisafactthat事实是d.It+不及物动词+that-从句Itappearsthat似乎Ithappensthat碰巧Itoccurredtomethat我突然想起八、名词性wh-从句1)由wh-词引导的名词从句叫做名词性wh-从句。Wh-词包括who,whom,.whose,whoever,what,whatever,which,whichever等连接代词和where,when,how,why等连接副词。Wh-从句的语法功能除了和that-从句一样外,还可充当介词宾语、宾语补语和间接宾语等,
26、例如:主语:Howthebookwillselldependsonitsauthor.直接宾语:Inonesownhomeonecandowhatonelikes.间接宾语:Theclubwillgivewhoeverwinsaprize.俱乐部将给得胜者设奖。表语:MyquestioniswhowilltakeoverpresidentoftheFoundation.宾语补足语:Shewillnamehimwhatevershewantsto.同位语:Ihavenoideawhenhewillreturn.形容词宾语:Imnotsurewhysherefusedtheirinvitation
27、.介词宾语:Thatdependsonwhereweshallgo.2)Wh-从句作主语也常用先行词it做形式主语,而将wh-从句置于句末,例如:Itisnotyetdecidedwhowilldothatjob.Itremainsunknownwhentheyaregoingtogetmarried.九、if,whether引导的名词从句1)yes-no型疑问从句从属连词if,whether引导的名词从句是由一般疑问句或选择疑问转化而来的,因此也分别被称为yes-no型疑问句从句和选择型疑问从句,其功能和wh-从句的功能相同,例如:主语:Whethertheplanisfeasiblerem
28、ainstobeproved.宾语:Letusknowwhether/ifyoucanfinishthearticlebeforeFriday.表语:Thepointiswhetherweshouldlendhimthemoney.同位语:Theyareinvestigatingthequestionwhetherthemanistrustworthy.形容词宾语:Shesdoubtfulwhetherweshallbeabletocome.介词宾语:Iworryaboutwhetherhecanpassthroughthecrisisofhisillness.2)选择性疑问从句选择性疑问从句
29、由关联词if/whetheror或whetherornot构成,例如:Pleasetellmewhether/iftheyareSwedishorDanish.Idontcarewhetheryouliketheplanornot.if和whether的区别:1、在动词不定式之前只能用whether。如:例8Icantdecidewhethertostay.2、在whetherornot的固定搭配中。如:例9Iwanttoknowwhetheritsgoodnewsornot.3、在介词后,只能用whether。如:例10Hisfatherisworriedaboutwhetherhelose
30、hiswork.。4、宾语从句放在句首表示强调时,只能用whether。如:Whetherthisistrueornot,Ireallydontknow.(例11Whethertheycanfinishtheworkontimeisstillaproblem.他们是否能准时完成这项工作还是个问题。此例为主语从句,有误,感谢指出)5、用if会引起歧义时,只用whether。如:例12Couldyoutellmeifyouknowtheanswer?这句话有两种意思:“你能告诉我是否知道答案吗?”或“如果你知道答案,请告诉我,好吗?”。如用whether可避免歧义.十、否定转移1)将think,b
31、elieve,suppose,expect,fancy,imagine等动词后面宾语从句的否定词转移到主句中,即主句的谓语动词用否定式,而从句的谓语动词用肯定式。IdontthinkIknowyou.我想我并不认识你。Idontbelievehewillcome.我相信他不回来。注意:若谓语动词为hope,宾语从句中的否定词不能转移。Ihopeyouwerentill.我想你没有生病吧。2)将seem,appear等后的从句的否定转移到前面。Itdoesntseemthattheyknowwheretogo.看来他们不知道往哪去。Itdoesntappearthatwellhaveasunny
32、daytomorrow.看来我们明天不会碰上好天气。3)有时将动名词,介词短语或整个从句的否定转变为对谓语动词的否定。Idontrememberhavingeverseensuchaman.我记得从未见过这样一个人。(not否定动名词短语having)Itsnotaplacewhereanyonewouldexpecttoseestrangecharactersonthestreet.在这里,人们不会想到在街上会碰上陌生的人。(anyone作主语,从句中的谓语动词不能用否定形式。)4)有时状语或状语从句中否定可以转移到谓语动词前。Theantisnotgatheringthisforitselfalone.(否定状语)蚂蚁不只是为自己采食。HewasnotreadytobelievesomethingjustbecauseAristotlesaidso.(否定because状语)他并不因亚里斯多德说过如何如何,就轻信此事。Shehadnotbeenmarriedmanyweekswhenthatmansyoungerbrothersawherandwasstruckbyherbeauty.(否定状语manyweeks)她结婚还不到几个星期,这个人的弟弟就看见她了,并对她的美貌着了迷。