Unit4Astronomy:thescienceofthestarsGrammarThesubjectclause主语从句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。1.引导主语从句的连接词有三类:(1)连词that、whether:Thattheywereintruthsisterswasclearfromthefacialresemblancebetweenthem.Whetherhe’llcomehereisn’tclear.Thatpricewillgoupiscertain.Whetherwegobytrainorbyboatmakesnodifference.Whowillwritethepoemhasnotbeendecidedyet.Whateverhedidisright.Whatshedidisnotyetknown.Whoevercomesiswelcome.Whicheveryouwantisyours(2)连接代词who,whom,whose,what,which,whoever,whatever,whichever等3)连接副词where,when,how,why等。Howthishappenedisnotcleartoanyone.Whereveryouareismyhome----myonlyhome.Whenhewillbebackdependsontheweather.Wherewelivedoesn’tmatter.Howthepyramidswerebuiltwasstillamystery.A.It+be+形容词(obvious,true,natural,surprising,good,wonderful,funny,possible,likely,certain,probable,etc.)+that从句。如:Itiscertainthatshewilldowellinherexam.Itisprobablethathetoldhereverything.B.It+be+名词词组(nowonder,anhonour,agoodthing,apity,nosurprise,etc.)+that从句。如:It’sapitythatwecan’tgo.It’snosurprisethatourteamshouldhavewonthegame.2.2.用用itit作形式主语的结构作形式主语的结构C.It+be+过去分词(said,reported,thought,expected,decided,announced,arranged,etc.)+that从句。如:ItissaidthatMr.GreenhasarrivedinBeijing.ItisreportedthatChinahassentanotherman-madeearthsatelliteintoorbit.D.It+seem,happen等不及物动词及短语+that从句。如:ItseemsthatAliceisnotcomingtothepartyatall.AliceIthappenedthatIwasoutthatday.E.It+doesn’tmatter(makesnodifference,etc.)+连接代词或连接副词引起的主语从句。如:Itdoesn’tmatterwhethershewillcomeornot.Itmakesnodifferencewhereweshallhavethemeeting.F.当that引导的主语从句出现在疑问句中时,要以it作形式主语,而把主语从句后置。如:Isittruethatthescientistwillgiveusalecturenextweek?Doesitmattermuchthattheywillnotcometomorrow?G.当主语从句出现在感叹句中时,要以it作形式主语,而把主语从句后置。如:Howstrangeitisthatthechildrenaresoquiet!3.3.主语从句不可位于句首的五种情况:主语从句不可位于句首的五种情况:(1)if引导的主语从句不可居于复合句句首。(2)Itissaid/reported…结构中的主语从句不可提前。例如:ItissaidthatPresidentJiangwillvisitourschoolnextweek.ThatPresidentJiangwillvisitourschoolnextweekissaid.(3)Ithappens/occurs…结构中的主语从句不可提前。例如:Itoccurredtohimthathefailedintheexamination.Thathefailedintheexaminationoccurredtohim.(4)Itdoesn’tmatterhow/whether…结构中的主语从句不可提前。例如:Itdoesn’tmatterwhetherheiswrongornot.Whetherheiswrongornotdoesn’tmatter.(5)含主语从句的复合句是疑问句时,主语从句不可提前。Isitlikelythatitwillrainintheevening?Isthatwillrainintheeveninglikely?√×√×√×√×4.主语从句需注意的问题(1)主语从句中用陈述语序WhatsheisafraidofistheirtakinghertoParis.(Whatissheafraidof…Wrong)(2)主语从句后谓语动词用第三人称单数Thattheyhaven’tphonedisstrange.(3)that引导的主语从句中,that不可被省略Thatpricewillgoupiscertain.4.It4.It作形式主语和作形式主语和itit引导强调句的比较引导强调句的比较It作形式主语代替主语从句,主要是为了平衡句子结构,主语从句的连接词没有变化。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。被强调部分指人是也可用who/whom。例如:Itisapitythatyoudidn’tgotoseethefilm.Itdoesn’tinterestmewhetheryousucceedornot.Itisinthemorningthatthemurdertookplace.ItisJohnthatbrokethewindow.5.what与that在引导主语从句时的区别what引导主语从句时在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:1)Whatyousaidyesterdayisright.2)Thatsheisstillaliveisaconsolation.Itisrightwhatyousaidyesterday.Itisaconsolationthatsheisstillalive.×√1.Whereshallwespendtheholidayisn’tdecided.2.Yourhavemadeamistakeisafact.3.Thatiscertainthatwecanwin.4.Nomatterwholeavestheroomlastoughttoturnoffthelights.5.Itisimportantthatastudentlearnsaforeignlanguage.weshallThatyouhaveItisWhoevershouldlearn改错练习1.Ireadaboutitinsomebookorother,doesitmatter_______itwas?(01北京春季)A.whereB.whatC.howD.which2.AfterYangLiweisucceededincirclingtheearth,_______ourastronautsdesiretodoiswalkinspace.(04上海)A.whereB.whatC.thatD.how3.Fashiondiffersfromcountrytocountrymayreflecttheculturaldifferencesfromoneaspect.(00上海)A.WhatB.ThatC.ThisD.Which(D)(B)(B)