语法|名词性从句用法归纳在复合句中起到名词作用的从句叫做名词性从句（nounclauses），可以分为主语从句、宾语从句、表语从句和同位语从句。一、名词性从句的基本用法（一）宾语从句（ObjectClause）宾语从句在复合句中起宾语的作用，作动词或介词的宾语。引导词有that,if,whether以及wh-词（含how）。如：Noonecantellwhatwillhappentothefrighteningvirus.Iamsurethatawell-designedexamcanchecktheresultofyourlearningonlinecourses.Theyarediscussingwhenweshouldstartthenewterm.注意点：1.that引导宾从时，常可省略，但是由and连接的多个宾从时，and后的that不能省略。如：Hesaid(that)hisfamilywasmovedfromSanFrancisco.Hesaid(that)hisfamilywasmovedfromSanFranciscoandthathissoncouldspeakEnglishfluentlyat2yearsold.2.if不能引导介词后的宾语从句，只能用whether。如：Theyarearguingoverwhethertheircountryshouldtakemorepowerfulmeasurestocontainthenovelvirus.但要注意特例exceptthat。如：Heisniceexceptthatheiseasytogetangry.3.注意make,consider,think,find,expect等动词后接复合宾语时，可以是it为形式宾语，that引导的从句为真正宾语。如：Nooneeverexpecteditsodangerousthatapatientwasinfectedwiththenovelvirus.（二）表语从句（ThePredicativeClause）在复合句中作表语的句子叫做表语从句，放在be,become,get,grow,appear,seem,sound,smell,feel,taste等连系动词后。引导词有that,whether,asif以及wh-词（含how）。如：Hervoicesoundsasifabirdissinging.ThefactisthatthelockdownofWuhanCityreallyworkstocontainthespreadofthenovelcoronavirus.注意点：1.that引导表语从句时，无实义，但不能省略。如：Mydreamisthatallmystudentscanbeadmittedintoakeyuniversity.2.what在引导的表语从句中表示“所⋯⋯的（人或事）”，在表语从句中充当主语或宾语。如：That’swhatmanypeopleareworriedabout.3.表示“原因”类的表语从句。要特别注意各自的固定搭配。如：Thisisbecausehedroppedoutofmanylessons.Thereasonisthathedroppedoutofmanylessons.Thatiswhyhefailedtheexamagain.（三）主语从句（TheSubjectClause）在复合句中作主语的句子叫做主语从句。引导词有that,whether以及wh-词（含how）。如：Howweshouldmakeuseofthewasteiscontroversial.注意点：1.that引导主语从句时，无实义，但不能省略。Thathewillbethenextpresidentiscertain.2.为避免主语显得过长，常用it作形式主语，把主语从句移到句子的末尾。如：Itisnotclearwhenwewillstartanewschoolterm.It’sapitythatyoufailedtheexamagain.It’ssaidthattheUKistakinganegativeattitudetowardsthebattleagainstthenovelcoronavirus.Itisoftenthecasethatanythingispossibleforthosewhohangontotheirdreams.（四）同位语从句（TheAppositiveClause）在主从复合句中，用作同位语的从句，叫做同位语从句。它一般跟在某些名词（如fact,idea,news,thought,hope,possibility,promise,suggestion,order,word等）后，说明或解释这些名词的具体内容，引导词有that以及wh-词（含how）。如：It’safactthatmenareusuallystrongerthanwomen.IhavenoideawhenwewillsetoutforShanghai.Wordcamethatthenewly-electedpresidentwouldpayanofficialvisittoChinathenextweek.（此句要注意that引导的同位语从句并没有紧跟在Word<消息>后，而是移至末尾，是为了避免句子显得头重脚轻）注意点：1.that在从句中不担当任何成分，不能省略。Thereisnopossibilitythatwewillwinthefootballgame.Thereisnodoubtthatyou'llmakeit.2.suggestion,order,proposal等词后接同位语从句时，要用虚拟语气，谓语动词形式为shoulddo,should可省略。如：Themanagerputforwardasuggestionthatweshouldhaveanassistantdealwithourheavytask.3.that引导同位语从句与定语从句的关键区别是同位语从句中that只起连接作用，不充当任何成分（不可省略），而定语从句中的that在从句充当主语或宾语，作宾语时还常可省略。同位语从句是说...
