Unit5TheBritishIslesTheThirdPeriod（GrammarNounClauses）一、名词性从句介绍名词性从句包括：主语从句，表语从句，同位语从句，多由连词that,wh-疑问词或由what,whatever等关系代词引导。⒈主语从句⑴主语从句在句子中充当主语，句子的谓语动词用第三人称单数。E.g.Whyherefusedtoworkwithyouisstillamystery.Whatevercomesiswelcome.⑵主语从句前的that不能省略，仅起连接作用，有时候为保持句子平衡，that从句后置而由it作形式主语。E.g.Thathebecamealawyermayhavebeenduetohismother’sinfluence.ItisnottruethathehasmovedtoNewYork.⒉宾语从句在句子中充当宾语E.g.Idon’tknowwherethesoundcamefrom.Don’tbesatisfiedwithwhatyouhaveachieved.⒊当从句放在系动词be,look,remain,seem等后构成表语从句。E.g.ThetroubleisthatIhavelosthisaddress.Itseemedthatthenightwouldneverend.⒋同位语从句⑴同位语从句是对与之同位的名词中心词作进一步解释，能接同位语从句的常见名词有idea,fact,news,belief,hope,evidence,opinion,problem,truth,proposal,theory,decision.discovery.problem,thought.understanding等。E.g.Thefactthatwetalkedaboutisveryimportant.(定语从句)Thefactthathesucceedintheexperimentpleasedeverybody.(同位语从句)⒌whether与if在名词性从句中的用法区别if一般指用于引导从句，而whether可引导包括宾语从句在内的其他名词性从句。⑴连词whether引导主语从句，表语从句时不能用if来替换。Whetherhewillattendthemeetingisuncertain.Thequestioniswhetherhewillcome.⑵宾语从句中，whether常与ornot搭配，也可以说whetherornot,而不说ifornot.E.g.Idon’tcarewhetherornotshewillattendthemeeting.⑶whether也可用在介词后，或带to不定式前，ifornot.E.g.Shedoesn’tknowwhethertogetmarriednoworwait.Ihaven’tsettledthequestionofwhetherI’llgobackhome.⑷某些动词后面（如discuss）只能用whether,不用if.E.g.Wediscussedwhetherweshouldgoonclimbing.二、主语从句高考考点用心爱心专心115号编辑在句中做主语的从句叫主语从句，是一种重要的名词性从句。⒈由what等连词引导的从句在主语从句中，what=thething(s)that,它本身在从句中充当成份，或是主语，或是表语，或是宾语，其含义为“所做/说/想的”。E.g.Whatyouhavedonemightdoharmtootherpeople.⒉由that引导的主语从句that在主语从句中不充当具体的句子成份，也无实义，只起连接作用，而且当它在句首时候，不能省略。E.g.Itworriedherabitthatherhairwasturninggrey.Thatyoudon’tlikehimisnoneofmybusiness.⒊由whether,if等引导的主语从句,句首用WhetherE.g.Whetherwe’llgocampingtomorrowdependsontheweather.⒋由whoever.whatever等引导的主语从句whoever=thepersonwho或anyonewho.who也可以引导主语从句，但只能表示“谁”E.g.Whowillwinisnotimportant.E.g.Whoeverleavestheroomlastoughttoturnoffthelights.Anyone与theperson皆不能引导从句。⒌由it作形式主语引起的主语从句that从句做主语时候，常用it做形式主语，而把that引导的主语从句放到句后。在下列情况下使用形式主语it，将主语从句放在句尾。⑴位于是seem，appear，be（im）possible，beapity，beawonder，belikely等。E.g.Itseemedcertainthatthiswouldwintheprize.Itappearedthathewasright.⑵在Itisknown…;Itissaid…;Itishoped…;Itisbelieved…等句型中。E.g.Itisstillaquestionwhenweshallhaveoursportsmeet.Itdoesn’tmatterwhatyousay.注意：有时候在“Itisnecessary(important.suggested等)＋that从句”结构中,that从句常用”should+动词原形”形式来表示虚拟语气,其中should常可省去.E.g.Itisnecessarythatacollegestudentshouldmasteratleastaforeignlanguage.用心爱心专心115号编辑
