名词性从句一．定义：在句子中起名词作用的句子叫名词性从句(NounClauses）。名词性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，名词性从句又可分别称为主语从句、宾语从句、表语从句和同位语从句。1.Hiswordsaretrue.Whathesaidistrue.2.Thedogsensedsomethingdelicious.Thedogsensedthattherewassomethingdeliciousnearby.3.Thesearehiswords.Thesearewhathesaid.4.MyChineseteacher,MrWang,isakindperson.Thenewsthattheplanehadcrashedmadeussad.二．引导名词性从句的连接词连词：在从句中不充当成分，只起连接作用that,无实义whether,if是否asif\asthough似乎，好像连接代词：有词义，在句中担任主语，表语，定语或宾语。what,什么who,谁whom,谁，作宾语whose,谁的which,哪一个whatever,whoever……也可以引导。连接副词：有词义，在句中担任状语。when,什么时候where,什么地方why,为什么how,怎么样howmany,howmuch,howoften三．主语从句1.作句子主语的从句叫主语从句。Whetherhewillcomeornotisnotknown.他来不来还不清楚。Whathewantstotellusisnotclear.他要跟我们说什么，还不清楚。Whowillwinthematchisstillunknown.谁能赢得这场比赛还不得而知。Itisknowntoushowhebecameawriter.我们都知道他是如何成为一名作家的。WheretheEnglisheveningwillbeheldhasnotyetbeenannounced.英语晚会将在哪里举行，还没有宣布。Thatheislateforschoolmakestheteacherveryangry.他上学迟到让老师很生气。2.有时为避免句子头重脚轻，常用形式主语it代替主语从句作形式主语放于句首，而把主语从句置于句末。主语从句后的谓语动词一般用单数形式。常用句型如下：（1）It+be+名词+that从句Eg.Itisapitythatwewon'tbeabletogotothesouthtospendoursummervacation.Itisstillamysterywhatcausedtheaccident.（2）It+be+形容词+that从句Eg.Itiscertainthathewillwinthematch.Itistruethathehasmadeaveryimportantdiscoveryinchemistry.Itisverylikelythattheywillholdameeting.Itisstrangethatheshoulddothat.Itisimportantthatweallshouldattendthemeeting.Itisstrangethatthemanshouldhavestucktohissillyideas.（3）It+be+动词的过去分词+that从句Eg.Itissaidthathehasgonetoshanghai.(=Heissaidtohavegonetoshanghai)ItisknowntoallthatthegunpowderwasfirstinventedbytheChinese.Itissuggestedthatthework（should）bedonewithgreatcare.（4）It+不及物动词+that从句Eg.Itseemsthathehasseenthefilm.(=Heseemstohaveseenthefilm)Ithappenedthatthetwocheatswerethere.(=Thetwocheatshappenedtobethere)ItoccurredtomethatIhadforgottentolockmydoor.ItsuddenlyhitmethatIhadforgottentolockmydoor.ItstruckmethatIhadforgottentolockmydoor.Itturnedoutthatnobodyrememberedtheaddress.注意：在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时，谓语动词要用虚拟语气“(should)+do”，常用的句型有：Itisnecessary(important,natural,strange,etc.)that…Itissuggested(requested,proposed,desired,etc.)that…3.主语从句的时态：不受主句的时态影响和限制。（1）Thathefinishedwritingthecompositioninsuchashorttimesurprisedusall.（2）Whetherwewillgoforanoutingtomorrowremainsunknown.（3）Whowillbeourmonitorhasn'tbeendecidedyet.（4）Whomwemuststudyforisaquestionofgreatimportance.（5）Whatcausedtheaccidentremainsunknown.（6）Whateveryoudidisright.（7）Whothewatchbelongstowaslostisunknown.4.that与what引导主语从句的区别what有词义，在句中担任主语，表语，定语或宾语。that无词义，不作任何成分，只起连接作用Eg.Whathasmadehimmadisnotknownyet.Thatsheisstillaliveisaconsolation.四．宾语从句1.定义：名词句用作宾语的从句叫宾语从句。2.由连接词that引导宾语从句时，that在句中不担任任何成分，在口语或非正式的文体中常被省去，但如从句是并列句时,第二个分句前的that不...
