1.概念在句子中起名词作用的句子叫名词从句(NounClauses）。名词从句的功能相当于名词词组,它在复合句中能担任主语、宾语、表语、同位语、介词宾语等,因此根据它在句中不同的语法功能,名词从句又可分别称为主语从句(SubjectClause)、宾语从句(ObjectClause)、表语从句(PredicativeClause)和同位语从句(AppositiveClause)。Whathewantstotellusisnotclear.Ibelieve(that)heishonest.Thequestioniswho(whichofyou)willbethenextspeaker.Thenewsthathehadlandedonthemoonspreadallovertheworld.主语从句宾语从句表语从句同位语从句2.引导名词性从句的连接词可分为三类:连接词/从属连词that,whether,if不充当从句的任何成分连接代词:what,whatever,who,whoever,whom,whose,which.连接副词:when,where,how,why3.不可省略的连词：1)介词后的连词2)引导主语从句和同位语从句的连词不可省略。Thatshewaschosenmadeusveryhappy.Weheardthenewsthatourteamhadwon.一、主语从句在复合句中作主语,它可以位于句首,但常见的主语从句多放在句末,句首则用形式主语it。1.Thattheearthisroundistrue.=Itistruethattheearthisround.主语从句的用法2.Whetherhewillcomehasn’tbeendecided.=Ithasn’tbeendecidedwhetherhewillcome.注意:连词that,whether在从句中不担任句子成分,只起连接作用,不能省略(注:if不可用来引导主语从句）二、用it作形式主语的结构(1)Itis＋名词＋从句Itisafactthat…事实是……Itisanhonorthat……非常荣幸Itiscommonknowledgethat…是常识(2)Itis＋形容词＋从句(多用should+V.)Itisnaturalthat…很自然……Itisstrangethat…奇怪的是……(3)Itis＋不及物动词＋从句Itseemsthat…似乎……Ithappenedthat…碰巧……Itappearsthat…似乎……(4)Itis＋过去分词＋从句Itisreportedthat…据报道……Ithasbeenprovedthat…已证实…Itissaidthat…据说……Itiscertainthathewillcome.ItissaidthatsomeAmericanfriendswillvisitourschoolnextweek.Ithappenedthatwewereoutforawalkyesterdayevening.Itdoesn’tmatterwhetherIstayornot.三、用带-ever的引导词(如whoever,whatever)引导的主语从句一般不后置。Whoeverleavestheroomlastshouldclosethedoor.Whateverwedomustbeintheinterestsof（为了…的利益）thepeople.四、it作形式主语和it引导强调句的比较it作形式主语代替主语从句,主要是为了平衡句子结构,主语从句的连接词有变化。而it引导的强调句则是对句子某一部分进行强调,无论强调的是什么成分,都可用连词that。被强调部分指人时也可用who/whom。例如:Itisapitythatyoudidn’tgotoseethefilm.（形式主语）Itdoesn’tinterestmewhetheryousucceedornot.（形式主语）Itisinthemorningthatthemurdertookplace.（强调句）ItisJohnthatbrokethewindow.（强调句）五、what与that在引导主语从句时的区别what引导主语从句时在从句中充当句子成分,如主语、宾语、表语,而that则不充当成分。例如：Whatyousaidyesterdayisright.Thatsheisstillaliveisaconsolation（安慰）.句子结构：主句+连接词(引导词)+宾语从句连接词分类:从属连词that,whether,if连接代词who,whom,whose,which,what连接副词where,how,why,when宾语从句的用法一、连词(引导词)1.当宾语从句是陈述句时(包括肯定句和否定句),连词由that引导,因为that在从句中不作任何成分,也没有任何具体意思,因此在口语或非正式文体中常省略。Hesaid(that)hewouldliketoseetheheadmaster.Janesaid(that)shewasn’tlateforthemeeting.2.当宾语从句是特殊疑问句时,由特殊疑问词充当连接词,因为该特殊疑问词(即连接词)在从句中担任一定的句子成分,具有一定的意义,所以不可以省略。Doyouknowwhathesaidjustnow?Idon’trememberwhenwearrived.IaskedhimwhereIcouldgetsomuchmoney.Pleasetellmewhowehavetosee.Doyouknowwhattimetheplaneleaves?3.当宾语从句是一般疑问句时,由连词whether或if引导(口语中常用if),因为if/whether翻译成“是否”,具有一定的意义,所以不能省略。Lilywantedtoknowif/whetherhergrandmalikedthehandbag.Let’sseeif...
