名词性从句详解.doc

名词性从句详解1.名词性从句的概念：概念：起名词作用的从句叫名词从句。它和名词一样，在句中可充当主语，表语，宾语和同位语。名词从句包括主语从句，表语从句，宾语从句和同位语从句。2.引导名词性从句的连接词可分为三类：连接词：that,whether,if连接代词：what,whatever,who,whoever,whom,whose,which.连接副词：when,where,how,why注意：that只起连接主句和从句的作用，在从句中不担任任何成分，本身也没有词义，宾语从句中可省略引导主语从句、表语从句和同位语从句,that不可省略3.主语从句在句中充当主语的从句叫做主语从句。主语从句可以放句首,但多数放句末.句首用形式主语IT.Thattheearthisroundistrue.=ItistruethattheearthisroundWhetherhewillcomehasn’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。并且whether引导主语从句时不能用if代替。WholetoutthenewsremainedunknownHowthishappenedisstillaquestionWhyhedidn’tcomehereisnotcleartoanyone注意：who,which,how,when,where,why在所引导的主语从句中可担任主语，宾语，状语，不能省略。可以用形式主语it引导。WhathesaidatthemeetingisimportantWhenevertheOlympicGameswillbeheldinBeijingisnotknownyet.注意：who,whom,which,what等可以和ever构成合成词，引导主语从句和宾语从句。此类主语从句不能用it引导，引导词在句中担任句子成分，不能省略。疑问词+ever和nomatter+疑问词的区别。①疑问词+ever可引导名词性从句和让步状语从句，在主从句中要充当一定的部分。③nomatter+疑问词只能引导让步状语从句。WhoeverbreakstherulemustbepunishedYoucanchoosewhateveryoulikeintheshop.Nomatterwhatyoudo,youmustdoitwell.It…＋主语从句”已成为固定结构It+is+形容词＋thatItisnecessarythat…有必要…Itisimportantthat….重要的是…Itisobviousthat……很明显……It+is+-ed分词＋that从句Itisbelievedthat…人们相信…Ithasbeendecidedthat……已经决定……Itisknowntous/allthat….众所周知…It+is+名词＋that从句Itiscommonknowledgethat……是常识Itisafactthat……事实是……Itisasurprisethat….令人惊奇的是…It+不及物动词＋that从句Itappearsthat…似乎…Ithappensthat….碰巧…Itoccurredtomethat……我突然想起……2.表语从句：主语＋连系动词＋表语从句在句中充当表语的从句(多数放在be动词后面)叫做表语从句。That’swhatweshoulddo.Ourpurposeisthathecanrealizehisfaults.注意：引导表语从句的连接词一般不省略。That’swhyIwanttoseeyou.Thequestioniswhetheritisworthdoing注意：表语从句表示“是否”只用“whether”而不用“if”1.be,seem,look等动词后均可跟表语从句：MysuggestionisthatweshouldgoshoppingItseemsthatitisgoingtorain2.asif,because也可引导表语从句。Itlooksasifit’sgoingtorain.注意：在表语从句中，当reason作主语时，引导词只能用that，不能用because，Itisbecausethereasonisthat…如：Thereasonwhyhewaslatewasthathedidn’tcatchtheearlybus.试区分以下句子Isthismuseumwhatyouvisited?Isthisthemuseumthatyouvisited?Isthismuseumtheonethatyouvisited?注意:把句子变换成陈述句，接着判断句子是属