高一二李冬各概述：名词从句相当于名词，可分别作主句的主语、宾语、表语和同位语从句?aid="sogousnap0_15">名词性从句均不能用逗号与句子的其他成份隔断，从句中的主谓语不能用倒装语序。引导词有：连接词that,if,whether,asif;疑问代词who,whom,what,which疑问副词when,where,how,why等。从属连词that无词义，在从句中不担任成分，有时可省略；whether（if）,asif虽有词义，但在从句中也不担任成分。主语从句主语从句是在复合句中充当主语的从句，通常放在主句谓语动词之前或由形式主语it代替，而本身放在句子末尾。主语从句做主句的主语。如：Whatwehavedoneisintheinterestofthepeople.1)引导主语从句的词有：连词：that,whether代词：what,who,which副词：when,where,how,why例如：Thattheearthturnsaroundthesunisknowntoall.Whetherhewillcomeornotisnotyetknown.Whowillgoisnotimportant.Whatweneedismorepractice.Whoeverisheregetsaprize.WhateverIhavedoneisonlyforyou.WhenhewillleavefortheUnitedStatesisnotyetdecided.Whyhefailedthephysicsexamwasn'tclear.Wherehehasbeenisstillapuzzle.HowThomasEdisonbecameagreatinventorisknowntoall.由于主语从句位于句首，句子常显得笨重，因此常把它移至句子后部，句首用引导词it来作形式主语。如：Itisapitythatshehasmadesuchafoolishmistake.It'sreportedthatthreepeoplewerekilledinthetrafficaccident.Itdoesn'tmatterwhetherhe'llcomeornot.IthappenedthatIdidn'ttakeanymoneywithme.Itseemsthatourfootballteamwillwinthematch.(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)It＋过去分词＋从句Itisreportedthat…据报道…Ithasbeenprovedthat…已证实…Itissaidthat…据说…4.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则不然。例如：Whatyousaidyesterdayisright.Itisrightwhatyousaidyesterday.×宾语从句宾语从句就是在复合句中作宾语的名词性从句，通常放在主句谓语动词(及物动词)或介词之后。1）引导宾语从句的词有：连词：that,whether,if代词：who,whose,what,which副词：when,where,how,why例如：Ithink(that)watchingTVtoomuchisbadforpeople'shealth.Iwonderifyoucandomeafavour.Iwonderwhathashappenedtoher.Heaskedmewhosehandwritingwasthebestintheclass.Iwonderwhysherefusedmyinvention.Canyoutellmewherethenearestpostofficeis?DoyouknowwhenhewillleaveforHongKong?WouldyoupleasetellmehowIcanfinishtheworkintheshortestpossibletime.Tomisaniceboy,exceptthatheissometimeslateforschool.Itdependsonwhetherthemanager