搜索
主语从句一、主语从句的连词分三类（1）从属连词引导的主语从句（thatwhetherif）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。Thatshesurvivedtheaccidentisamiracle.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。Whethersheiscomingornotdoesn’tmattertoomuch.（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Whateverwedoistoservethepeople.注：whatever/whoever的功用whatever=anythingthat;whoever=anyonewho。要注意和whatever,whoever引导的让步状语从句的区别。如：Whoeverbreaksthelawshouldbepunished.（主语从句）（＝Anyonewhobreaksthelawshouldbepunished.）Whoeverbreaksthelaw,heshouldbepunished.（让步状语从句）（＝Nomatterwhobreaksthelaw,heshouldbepunished.）（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:Whereweshouldleaveitisaproblem.Whentheywillcomehasn’tbeenmadepubic.三、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：aItis+名词+从句Itisafactthat…事实是……；Itisgoodnewsthat………是好消息；Itisaquestionthat………是个问题；Itiscommonknowledgethat………是常识类似的名词还有：apity；awonder；agoodthing；nowonder；surprise等。Itisamysterytomehowitallhappened.Itiscommonknowledgethatthewhaleisnotafish.ItisnosurprisethatBobshouldhavewonthegame.bItis+形容词+从句Itisnecessarythat…有必要……；Itisclearthat…很清楚……；Itislikelythat…很可能……；Itisimportantthat…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.Itisdoubtfulwhethershewillbeabletocome.Itisessentialthatheshouldbeherebytheweekend.Itseemsobviousthatwecannotgoonlikethis.Itisnecessarythatyou（should）masterthecomputer.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。cItis+过去分词+从句Itissaidthat…据说……；Itisreportedthat…据报道……；Ithasbeenprovedthat…已证明……；Itmustbeprovedthat…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;madeclear;foundout,etc.例如：Itisusedtobethoughtthatanewstarmustbeduetoacollisionbetweentwostars.Ithasnotbeenmadeclearwhenthenewroadistobeopenedtotraffic.dItseems不及物动词（happened/appears/doesn’t’tmatter/makesnodifference/occurred…）that…主语从句不可提前Itmakesnodifferencewhetherhewillattendthemeetingornot.ItdoesnotmatterifImissedmytrain.IthappenedthatIsawhimyesterday.(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：Whethertheywouldsupportuswasaproblem.他们是否会支持我们还是一个问题。Itwasaproblemwhethertheywouldsupportus.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：Whatweneedismoney.我们需要的是钱。WhatIwanttoknowisthis.我想知道的就是这一点。有时也可将助用形式主语。如：Itisclearenoughwhathemeant.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：Isittruethatheisthegirl’sfather?他是那女孩的父亲，是真的吗？Howisitthatyouarelateagain?你怎么又迟到了？四、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：Thatyoudidn’tgotothetalkwasapity.很遗憾你没去听报告。(that不可省)Itwasapity(that)youdidn’tgotothetalk.很遗憾你没去听报告。(that可省)高考题：1、Itneveroccurredtome___youcouldsucceedinpersuadinghimtochangehismind.(陕西高考)A．whichB．whatC．thatD．if2、It'sobvioustothestudents________theyshouldgetwellpreparedfortheirfuture.(天津卷)A．asB．thatC．whichD．whether3、________somepeopleregardasadrawbackisseenasaplugbymanyothers.(2010·北京)A．WhetherB．WhatC．ThatD．How4、Itisuncertain________sideeffectthemedicinewillbringabout，althoughabouttwothousandpatientshavetakenit.(2010·浙江)A．thatB．howC．whatD．whether主语从句练习题1.________makesmistakesmustcorrectthem.A.WhatB.ThatC.WhoeverD.Whatever2.Itworriedherabit____herhairwasturninggrey.A.whileB.thatC.ifD.for3.Whenandwhyhecamehere________yet.A.isnotknownB.arenotknownC.hasnotknownD.havenotknown4.________isnoreasonfordismissingher.A.BecauseshewasafewminuteslateB.OwingtoafewminuteslateC.ThefactthatshewasafewminuteslateD.Beingafewminuteslate5.________Tomlikedtoeatwasdifferentfrom________.A.That…thatyouhadexpectedB.What…thatyouhadexpectedC.That…whatyouhadexpectedD.What…whatyouhadexpected6.________wegoswimmingeveryday________usalotofgood.A.If...doB.That...doC.If...doesD.That...does7.It________Bobdrivesbadly.A.thinksthatB.isthoughtwhatC.thoughtthatD.isthoughtthat8.It'suncertain________theexperimentisworthdoing.A.ifB.thatC.whetherD.how9.________theboydidn'ttakemedicinemadehismotherangry.A.ThatB.WhatC.HowD.Which10.____wecan'tgetseemsbetterthan____wehave.A.What,whatB.What,thatC.That,thatD.That,what11.____youdon'tlikehimisnoneofmybusiness.A.WhatB.WhoC.ThatD.Whether12..____we'llgocampingtomorrowdependsontheweather.A.IfB.WhetherC.ThatD.Where13._________isgoingtodothejobwillbedecidedbythePartycommittee.A.ThatB.WhyC.HowD.Who14._______we'llfinishtranslatingthebookdependsonthetime.A.WhenB.WhyC.WhatD.That15.______hewon'tgothereiscleartoallofus.A.HowB.WhatC.WhyD.This16.______thehousewillbebuiltwillbediscussedattomorrow'smeeting.A.IfB.WhereC.ThatD.What17.._______youcomeornotisuptoyou.A.WhatB.IfC.WhyD.Whether18.._______makesmistakesmustcorrectthem.A.WhoB.AnyoneC.WhoeverD.Anybody19.._______teamwillwinthematchisamatterofpublicconcern.A.WhichB.ThatC.IfD.How20..________leavestheroomlastoughttoturnoffthelights.A.AnyoneB.ThepersonC.WhoeverD.Who答案：高考题：CBBA1~5CBACD6~10DDCAA11~15CBD