高中語法主語從句講解如果一個句子在復(fù)合句中充當(dāng)一個主語,那么這個句子就是主語從句。①Thathefinishedwritingthecompositioninsuchashorttimesurprisedusall.

②Whatweneedaregooddoctors.③Whomwemuststudyforisaquestionofgreatimportance.1.主語從句的連接詞1).連接詞:that,whether①.Thathewillwiniscertain.②.Whetherhe’lljoinusinthediscussionisofgreatimportance.2).連接代詞:who,what,which,whom,whose,whoever,whatever,whichever①.Itisclearwhoisafraidofhavingachangeinlandownership.②.WhatIndianeedsisalawtomakelandownershipfairer.3).連接副詞:when,where,why,how,howmany,howmuch,howlong,howsoon,howoften①Whenwe’llstarttomorrowwillbetoldsoon.②Wherewecanbuyoxenissomethingweneedtofindout.③Whyhecamehereisnotknown.④Howwecanprotectthegrainfromdampneedstobediscussed.【連接詞】1.that——Thattheearthmovesaroundthesuniswellknown.2.whether——Whetherhewillcomeornotisnotknownyet.3.who——Whowillbesenttherehasnotbeendecided.4.what——Whatyouneedismorepractice.5.which——Whichoneisthebestisnotclear.6.when,where——Wherehehasgoneisaquestion.7.why,how——Whythereisgravityishardtounderstand.HowhecanearnalivinginBritainremainsabigproblem.8.whoever、whatever、whichever可引導(dǎo)主語從句。Whoevercomeswillbewelcome.Whateverhedidwasright.Whicheverofyoucomesinwillreceiveaprize.【小結(jié)】1.引導(dǎo)主語從句連詞有that,whether,who,what,whatever等。2.連詞位于句首不能省略。3.主語從句大多數(shù)情況下視為第三人稱單數(shù),但在連接代詞what引導(dǎo)的主語從句后謂語動詞的數(shù)要根據(jù)句意而定?！餅榱朔乐咕渥宇^重腳輕，通常把形式主語it放在主語位置，真正主語后置。1.Itiscertainthathewillwinthematch.2.Itistruethathehasmadeaveryimportantdiscoveryinchemistry.3.Itisverylikelythattheywillholdameeting.4.Itisstrangethatthemanshouldhavestucktohissillyideas.5.Itisapitythatwewon'tbeabletogotothesouthtospendoursummervacation.6.Itisstillamysterywhatcausedtheaccident.7.ItissaidthathehasgonetoShanghai.8.Itseemsthathehasseenthefilm.【小結(jié)】1.以that引出的主語從句,常以形式主語it引導(dǎo),結(jié)構(gòu)為：Itis+形容詞/名詞/某些動詞ed+that從句。2.在有些that從句中要用虛擬語氣

(should+do/should+havedone)?！镉胕t作形式主語的結(jié)構(gòu)(1)Itis＋名詞＋從句Itisafactthat…事實是…Itisanhonorthat…非常榮幸(2)Itis＋形容詞＋從句Itisnaturalthat…很自然(2)Itis＋形容詞＋從句Itisnaturalthat…很自然…Itisstrangethat…奇怪的是…(3)It＋不及物動詞＋從句Itseemsthat…似乎…Ithappenedthat…碰巧…(4)It＋be+過去分詞＋從句Itisreportedthat…據(jù)報道…(4)It＋be+過去分詞＋從句Itisreportedthat…據(jù)報道…Ithasbeenprovedthat…已證實…Itissaidthat…據(jù)說…★“It”作形式主語代替主語從句的常見句型舉例①It’s+adj.+that/wh-clausee.g.It’sclear/natural/certainthatclause②It’s+p.p.+that/wh-clausee.g.It’ssaid/reported/knownthatclauseIt’sbelievedthathewillcomenextweek.②It’s+p.p.+that/wh-clausee.g.It’ssaid/reported/knownthatclauseIt’sbelievedthathewillcomenextweek.③It‘s+n.+that/wh-clausee.g.It’sashame/anhonour/goodnewsthatclauseIt’sstillaquestionwhenwe’llhaveourmeeting.④④It+v.(n./pron.)that/wh-clausee.g.Itmadeusveryhappythatshewaschosen.Itappearsthatheforgottosigntheletter.★whether與if均為“是否”，但下列情況下只用whether：1.引導(dǎo)主語從句并在句首——Whetherhewillcomeisnotclear.2.引導(dǎo)表語從句——Thequestioniswhetherhe’llcome.3.whether從句作介詞賓語——I’mnotsureaboutwhetherwe’llwin.4.引導(dǎo)讓步狀語從句時——Whetheryoulikeitornot,you’llhavetodoit.【注意事項】1.主語從句位于句首時必須由連接詞引導(dǎo)。2.主語從句后置時引導(dǎo)詞that可省略。3.主語從句位于句首時,不能用if引導(dǎo)。4.主語從句后置時,可以用if引導(dǎo)。練一練1.Whatmakesthisshopdifferentisthatitoffersmorepersonalservices.2.ThesewildflowersaresospecialIwoulddowhateverIcantosavethem.3.Itisrequiredintheregulationsthatyoushouldnottellpeoplethepassportofyoure-mailaccount.4.Itisprettywellunderstoodwhatcontrolstheflowofcarbondioxideinandoutoftheatmospheretoday.5.Whatmadetheschoolproudwasthatmorethan90%ofthestudentshadbeenadmittedtokeyuniversities.6.Itnowappearsthattheyareinneedofhelp.7.Whoeverknowsthetruthwilltellyouaboutit.8.Itisgoodnewsthattheywillarriveinafewdays.Usethewordsbelowtofillintheblanks1.______watchwaslostisunknown.2.________youdidisright.3._________wewillgoforanoutingtomorrowremainsunknown.4.______weneedistime.5.______willbeourmonitorhasn'tbeendecidedyet.whetherwhatwhowhosewhatever.WhetherWhatWhateverWhoseWho上面的空大家都填對了嗎?上面每個句子都出現(xiàn)了的主語從句，大家能找到嗎？1.Whosewatchwaslostisunknown.2.Whateveryoudidisright.3.Whetherwewillgoforanoutingtomorrowremainsunknown.4.Whatweneedistime.5.Whowillbeourmonitorhasn'tbeendecidedyet.1.Whosewatchwaslostisunknown.2.Whateveryoudidisright.3.Whetherwewillgoforanoutingtomorrowremainsunknown.4.Whatweneedistime.5.Whowillbeourmonitorhasn'tbeendecidedyet.2.在有些that從句中要用虛擬語氣

(should+do/should+havedone)。他出生在何地還不知道。2.誰會贏得比賽還不知道。3.誰來都歡迎。4.那個人為什么被謀殺尚不知道。Wherehewasbornhasnotbeenfound.Whythepersonwasmurderedisstillunknown.Whowillwinthematchisstillunknown.Whoevercomesiswelcome.5.Whattheteachersaidtodaywasquiteright.

老師今天說的話是十分正確的。6.Thattheyarebadlyinneedofhelpisquiteclear.他們急需幫助，這是十分明顯的。7.Whethertheywillsellthehouseisnotyetdecided.他們是否賣掉這所房子還沒有決定。8.Whateverwassaidheremustbekeptsecret.這里說的話都應(yīng)當(dāng)保密。9.Whoevermakesmis