初中英语从句讲解

知识要点：名词性从句包括：主语从句、表语从句、宾语从句和同位语从句。引导名词性从句的连词有：A.连词：that,whether,if（这三个词都不作从句的成分，同时，that无含义，而whether和if都表“是否”）B.疑问代词：who,whom,whose,what,whichC.疑问副词：when,where,why,how（一）主语从句：在复合句中充当主语的从句。1.that引导主语从句that引导主语从句时不同于其他的连词，既无词义也不作成分，只起单纯的连接作用，且通常不可以省。为了强调that引导的主语从句而置之于句首时，that不可省。①Thatthedrivercouldnotcontrolhiscarwasobvious.②Thatshewaschosenmadeusveryhappy.③Thathewillcomeiscertain.④Thathewouldtaketheriskistrue.⑤Thatheshouldhavemarriedherisn'tsurprising.★通常，that引导主语从句时用it做形式主语，把从句置于句尾，此时that有时可省。例如：①Itwasobviousthatthedrivercouldnotcontrolhiscar.②Itmadeusveryhappythatshewaschosen.③Itiscertainthathewillcome.④Itistruethathewouldtaketherisk.⑤Itisn'tsurprising(that)heshouldhavemarriedher.★如果以that从句为主语的句子是疑问句，就只能用先行词it结构。例如：①Isitcertainthathewillcome?②Isittruethathewouldtaketherisk?▲it做形式主语有以下几种不同的结构：(1)It+be+形容词+that-从句①Itislikelythathewillcome.②Itisstrangethatshehasevertrustedhim.③Itisimportantthathe(should)attendthemeeting.④Itisbestthathe(should)go.此句型在表示惊讶、喜悦、遗憾等感情色彩时，that从句中的谓语动词也常用(should)+v原形。Itisstrangethatnooneshouldhaveobjectedtotheplan.(2)It+be+名词+that-从句Itiscommonknowledgethatthewhaleisnotafish.It'sapitythatheshouldhavecatchedthetrain.(3)It+be+-ed分词+that从句Itissaidthatheisafamouswriter.Itisreportedthattherewillbeastormthisafternoon.▲在表示建议、要求、命令等意义的被动结构中，that从句中的谓语动词常用(should)do。（参见虚拟语气部分）Itissuggestedthatthemeeting(should)beheldthisafternoon.Itisdemandedthathe(should)leaveatonce.(4)It+seem/happen/appear等不及物动词+that从句。（look不接that从句，它接tobe结构或形容词）Itseemsthatheiswrong.Itappearsthattheyareinurgentneedofhelp.Helooks(tobe)surprised/happy/sad.2.whether引导主语从句，意为“是否”，只起连接作用，不充当任何成分。（置于句首时必须用whether引导，置于句尾时，间或可用if。）Whetherhewillwinthegameisnotclear.Whetherhewillcomeisuncertain.Whethershecomesornotdoesn'tconcernme.Itisnotclearwhether/ifhewillcome.Itwasuncertainwhetherhewouldcome.3.连词代词what,who,which,whose等引导的主语从句。这些连接代词作用相当于代词，在从句中担当主语、宾语、表语、定语等。Whatweneedismoretime.Whowasresponsiblefortheaccidentisnotyetclear.Whosebookitisnotimportant.Whichschoolyouwanttogomattersmuch.4.连接副词when,where,why,how引导的主语从句。这些连接副词相当于副词，在从句中充当状语。Whyhedidthisisnotknown.Whenhewillcomeisstillunknown.Itisnotknownwhyhedidthis.Howhesucceededisunknowntous.Whereweshouldholdthemeetingneedstobediscussed.注意：wh-引导的主语从句也常用it作形式主语。5.也可用whatever,whoever,whomever,whenever,wherever等词引导主语从句，表示“无论什么”、“无论谁”、“无论何时”、“无论在（到）哪里”等。Whoevertoldyoutogiveupsmokingwasquiteright.Whateverhegaveyoushouldbehandedin.Whoevertoldyouthatwaslying.Whoevercomesiswelcome.专项训练：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,what(后设答案，大家不要偷看(⊙o⊙)哦，(*^__^*)嘻嘻……)KEYS1.C2.B3.A4.C5.D6.D7.D8.C9.A10.A（二）表语从句：在复合句中充当表语。1.that在引导表语从句时无含义，不作成分，通常不省。1)表示事实、真理等的实际内容。Thefactisthatheislying.Theoddsarethathewillnotdoit.2）表示某人的意见、信念等的实际内容。Ourbeliefisthatthingswillimprove.Thetroubleisthatweareshortofmoney.2.whether引导表语从句（不可用if)。HisfirstquestionwaswhetherHolmeshadarrivedyet.Thequestioniswhetherpeoplewillbuyit.3.连接代词who,whom,whose,what,which引导的表语从句。ThisiswhatIwant.Thequestioniswhocanbechosentobemanagerofthecompany.Myquestioniswhichofthemisbetter.4.连接副词when,where,why,how引导的表语从句。Theproblemseemedhowwecouldmakehimunderstandit.Thequestioniswhereweshouldgo.5.asif,asthough引导的表语从句（常用虚拟语气）。Helooksasifhewereangry.Itlooksasifit'sgoingtorain.专项训练：1.Thequestionis______wewillhaveoursportsmeetnextweek.A.thatB.ifC.whenD.whether2．Thereasonwhyhefailedis______hewastoocareless.A.becauseB.thatC.forD.becauseof3.Goandgetyourcoat.It's______youleftit.A.whereB.thereC.therewhereD.wherethere4．Theproblemis______totaketheplaceofTedA.whocanwegetB.whatwecangetC.whowecangetD.thatwecanget5.WhatIwanttoknowis______helikesthegiftgivenbyus.A.thatB.ifC.whetherD.不填6.Thereasonis______Imissedthebus.A.thatB.whenC.whyD.what7.Thatis______wewerelatelasttime.A.thatB.whenC.whyD.what8.Shelooked______sheweretenyearsyounger.A.thatB.likeC.asD.asthough9.--Ifellsick!--Ithinkitis______youaredoingtoomuch.A.whyB.whenC.whatD.because10.Thereasonwhyhehasn’tcomeis______.A.becausehismotherisillB.becauseofhismother’sbeingillC.thathismotherisillD.forhismotherisill11.--Hewasbornhere.--Thatis______helikestheplacesomuch.A.thatB.whatC.whyD.how12.Thatis______LuXunoncelived.A.whatB.whereC.thatD.why(后设答案，大家不要偷看(⊙o⊙)哦，(*^__^