主語從句講解及其練習(xí)

第8頁主語從句一、主語從句的連詞分三類〔1〕附屬連詞引導(dǎo)的主語從句〔thatwhetherif〕that引導(dǎo)的主語從句:引導(dǎo)詞that無含義/在句中不做成分/不可以省。That引導(dǎo)主語從句通常用it作形式主語。

例如：Thatyouwillwinthemedalseemsunlikely.Thatshesurvivedtheaccidentisamiracle.

whether引導(dǎo)的主語從句:whether有含義(是否)/在句中不做成分/不可以省。注意：引導(dǎo)主語從句，不能用if不能在開頭，只能用whether。Whetherwewillholdapartyintheopenairtomorrowdependsontheweather.Whethersheiscomingornotdoesn’tmattertoomuch.

〔2〕用連接代詞引導(dǎo)的主語從句在由連接代詞who,whose,whom,which,what,whoever,whomever,whichever,whatever引導(dǎo)的名詞性從句中，其連接代詞在句中起名詞性作用，擔(dān)當(dāng)一定成分.

例如：Whatyouneedismorepractice.

Whateverwedoistoservethepeople.

注：whatever/whoever的功用whatever,whoever在主語從句中不含疑問意義。它引導(dǎo)主語從句，并在從句中作主語、賓語、表語等。whatever=anythingthat;whoever=anyonewho。要注意和whatever,whoever引導(dǎo)的讓步狀語從句的區(qū)別。如：Whoeverbreaksthelawshouldbepunished.〔主語從句〕〔＝Anyonewhobreaksthelawshouldbepunished.〕Whoeverbreaksthelaw,heshouldbepunished.〔讓步狀語從句〕〔＝Nomatterwhobreaksthelaw,heshouldbepunished.〕〔3〕用連接副詞when,where,why,how引導(dǎo)的名詞性從句(其連接副詞有含義,在句中作狀語。)例如:Whereweshouldleaveitisaproblem.Whentheywillcomehasn’tbeenmadepubic.三、it作形式主語的主語從句有時(shí)為了考慮句子平衡，通常在主語從句處使用形式主語it，而將真正的主語從句移至句末。這分四種情況：(1)對(duì)于以連詞that引導(dǎo)的主語從句，通常用形式主語it替代主語從句：<a>Itis+名詞+從句Itisafactthat…事實(shí)是……；Itisgoodnewsthat………是好消息；Itisaquestionthat………是個(gè)問題；Itiscommonknowledgethat………是常識(shí)類似的名詞還有：apity；awonder；agoodthing；nowonder；surprise等。Itisamysterytomehowitallhappened.Itiscommonknowledgethatthewhaleisnotafish.ItisnosurprisethatBobshouldhavewonthegame.<b>Itis+形容詞+從句

Itisnecessarythat…有必要……；Itisclearthat…很清楚……；Itislikelythat…很可能……；Itisimportantthat…重要的是……

類似的形容詞還有：strange;natural;obvious;true;good;wonderful;possible;unlikely;quite;unusual;certain;evident;worth-while;surprising;interesting;astonishing,etc.Itisdoubtfulwhethershewillbeabletocome.

Itisessentialthatheshouldbeherebytheweekend.

Itseemsobviousthatwecannotgoonlikethis.Itisnecessarythatyou〔should〕masterthecomputer.需要注意的是這類主語從句中，謂語動(dòng)詞很多為“〔should〕＋動(dòng)詞原形〞，即要用虛擬語氣。<c>Itis+過去分詞+從句

Itissaidthat…據(jù)說……；Itisreportedthat…據(jù)報(bào)道……；Ithasbeenprovedthat…已證明……；Itmustbeprovedthat…必須指出……

類似的過去分詞還有：known;estimated;expected;believed;thought;hoped;noted;discussed;required;decided;suggested;demanded;madeclear;foundout,etc.

例如：Ithasnotbeenmadeclearwhenthenewroadistobeopenedtotraffic.

<d>Itseems不及物動(dòng)詞〔happened/appears/doesn’t’tmatter/makesnodifference/occurred…〕that…主語從句不可提前Itmakesnodifferencewhetherhewillattendthemeetingornot.ItdoesnotmatterifImissedmytrain.

IthappenedthatIsawhimyesterday.(2)對(duì)于以連接代詞(副詞)引導(dǎo)的主語從句，可以使用形式主語代主語從句，也可直接在句首使用主語從句：Whethertheywouldsupportuswasaproblem.他們是否會(huì)支持我們還是一個(gè)問題。Itwasaproblemwhethertheywouldsupportus.他們是否會(huì)支持我們還是一個(gè)問題。(3)對(duì)關(guān)系代詞型what引導(dǎo)的主語從句，通常直接將主語從句放在句首。如：Whatweneedismoney.我們需要的是錢。WhatIwanttoknowisthis.我想知道的就是這一點(diǎn)。有時(shí)也可將助用形式主語。如：Itisclearenoughwhathemeant.他是什么意思很清楚。(4)如果句子是疑問句，那么必須用帶形式主語it的構(gòu)造：Isittruethatheisthegirl’sfather?他是那女孩的父親，是真的嗎？Howisitthatyouarelateagain?你怎么又遲到了？四、連詞that的省略問題引導(dǎo)主語從句的連詞that有時(shí)可省，有時(shí)不能省，其原那么是：假設(shè)that引導(dǎo)的主語從句直接位于句首，那么that不能省略；假設(shè)that引導(dǎo)的主語從句位于句末，而在句首使用了形式主語it，那么that可以省略：Thatyoudidn’tgotothetalkwasapity.很遺憾你沒去聽報(bào)告。(that不可省)Itwasapity(that)youdidn’tgotothetalk.很遺憾你沒去聽報(bào)告。(that可省)高考題：1、Itneveroccurredtome___youcouldsucceedinpersuadinghimtochangehismind.(陜西高考)A．which B．whatC．that D．if2、It'sobvioustothestudents________theyshouldgetwellpreparedfortheirfuture.(天津卷)A．a(chǎn)sB．thatC．whichD．whether3、________somepeopleregardasadrawbackisseenasaplugbymanyothers.(2021·北京)A．WhetherB．WhatC．ThatD．How4、Itisuncertain________sideeffectthemedicinewillbringabout，althoughabouttwothousandpatientshavetakenit.(2021·浙江)A．that B．howC．what D．whether主語從句練習(xí)題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.When