名词性从句精讲精析.doc

名词性从句精讲精析主语从句、宾语从句、 表语从句、同位语从句名词性从句是由if,whether,that和各种疑问词充当连接词所引导的从句（what，which，who，whose；when，where，how，why等），其功能同名词一样。一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.It作形式主语和it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：Itisapitythatyoudidntgotoseethefilm.Itdoesntinterestmewhetheryousuccedornot.Itisinthemorningthatthemurdertookplace.ItisJohnthat/whobrokethewindow.2.用it作形式主语的结构(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It is obvious that明显的是It is important that重要的是It is necessary that必要的是(3)Itis不及物动词从句Itseemsthat 似乎Ithappenedthat 碰巧It appears that 好象/看来 (4)It is过去分词从句Itisreportedthat 据报道Its said that 据说Its believed that 人们相信Its hoped that 人们希望Its thought that 人们认为 Its announced that 据宣布Ithasbeenprovedthat 已证实3.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：ItissaidthatPresidentJingowillvisitourschoolnextweek.(right)ThatPresidentJiangwillvisitourschoolnextweekissaid.(wrong)(3)Ithappens,Itoccurs结构中的主语从句不可提前。例如：Itoccurredtohimthathefailedintheexami-nation.(right)Thathefailedintheexaminationoccurredtohim.(wrong)(4)Itdoesntmatterhow/whether结构中的主语从句不可提前。例如：Itdoesntmatterwhetherheiswrongornot.(right)Whetherheiswrongornotdoesntmatter.(wrong)(5)含主语从句的复合句是疑问句时，主语从句不可提前。例如：Isitlikelythatitwillrainintheevening?(right)Isthatwillrainintheeveninglikely?(wrong)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则充当任何成分。例如：1)Whatyousaidyesterdayisright.2)Thatsheisstillaliveisaconsolation(安慰).二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.作动词的宾语(1)由that引导的宾语从句（that通常可以省略）,例如：Iheardthathejoinedthearmy.(2)由what,whether(if)引导的宾语从句，例如：1)Shedidnotknowwhathadhappened.2)Iwonderwhetheryoucanchangethisnoteforme.(3)动词间接宾语宾语从句。例如：Shetoldmethatshewouldacceptmyinvitation.2.作介词的宾语例如：Oursuccessdependsuponhowwellwecancooperatewithoneanother.3.作形容词的宾语例如：Iamafraid(that)Ivemadeamistake.That引导的从句常跟在下列形容词后作宾语：anxious, aware, certain, confident, determined, glad, proud, surprised, worried, sorry, thankful, ashamed, disappointed, annoyed烦恼的, pleased,satisfied, content(满意的)等。也可以将此类词后的that从句的看作原因状语从句。4.It可以作为形式宾语It不仅可以作为形式主语，还可以作为形式宾语，而真正的宾语that从句则放在句尾，特别是在带复合宾语的句子中。例如：Wehearditthatshewouldgetmarriednextmonth.I dont think it(形式宾语) necessary(宾语补足语) that you should go now(宾语从句).I find it difficult that you want to do the job well. 我发现你想做好这件事不容易。I think it best that you should stay here. 我认为你最好住这儿。She felt it her duty that she takes good care of them. 她感到好好照顾他们是她的责任。We think it no use that you complain. 我们认为你抱怨是没有用的。5.否定的转移若主句谓语动词为think,consider,suppose,believe,expect,fancy,guess,imagine等，其后的宾语从句若含有否定意义，一般要把否定词转移到主句谓语上，从句谓语用肯定式。例如：Idontthinkthisdressfitsyouwell.（我认为这件衣服不适合你穿。）6.几种特殊的形式宾语以下几类形式宾语却比较特殊，其后没有宾语补足语。1). 动词+ it + that-从句I like it that you came. 你来了，我很高兴。I take it (that) he will come on time. 我认为他会准时来的。You can put it that it was arranged before. 你可以说这是以前安排的。Rumor has it that the defence minister will soon resign. 据传闻，国防部长不久就要辞职。【注】能用于此结构的动词不多，常见的有 have, take, put, like 等。2). 动词 + it + when (if)-从句I dislike it when you whistle. 我不爱听你吹口哨。We really appreciate it when she offered to help. 她来帮忙了，我们十分感激。Id prefer it if I didnt have to do so much work. 要是我不必做那么多工作，好就太好了。【注】能用于此结构的动词不多，常见的有 enjoy, hate, love, like, dislike, appreciate, prefer 等。I hate_ when people talk with their mouths full. (NMET 1998)A. it B. that C. theseD. them 我讨厌人们一边吃饭一边说话。(答案为: A) I like _ in the autumn when the weather is clear and bright. (全国卷 2004)A. this B. that C. itD. one 我喜欢秋天晴朗的天气。(答案为: C)3). 动词 + prep + it + that-从句See to it that youre not late again. 注意千万不要再迟到。Look to it that this doesnt happen again. 注意不要再发生这种事。I cant answer for it that he will come. 我不能保证他会来。You may rely on it that hell come to meet you. 你放心，他会来接你的。【注】能用于此结构的动词不多，常见的有see to, look to, insist on, stick to, depend on, answer for 等。4). 动词 + it + 介词短语+ that-从句I owe it to you that I am still alive. 多亏有你我才仍然活着。I took it for granted that he would help us. 我认为他会帮助我们的。【注】能用于此结构的动词不多，常见的有take it for granted, bring it to sbs attention, owe it to sb 等。三表语从句表语从句在复合句中作表语的名词性从句，放在系动词之后，一般结构是“主语连系动词表语从句”。可以接表语从句的连系动词有be, look,remain,seem等。引导表语从句的that常可省略。 另外，常用的还有Thereasonisthat和Itisbecause等结构。例如：1)Thequestioniswhetherwecanmakegoodpreparationinsuchashorttime.2)Thisiswhywecantgetthesupportofthepeople.3)Butthefactremainsthatwearebehindtheotherclasses.4)Thereasonheislateforschoolisthathemissedtheearlybus.四同位语从句同位语从句就是在复合句中作名词的同位语的名词性从句。1.同位语从句的功能同位语从句对于名词进一步解释，说明名词的具体内容，一般由that引导，例如：1)Thekingsdecisionthattheprisonerwould besetfreesurprisedallthepeople.2)Theorderthatallthesoldiersshouldstay stillisgivenbythegeneral.2.同位语在句子中的位置同位语从句有时可以不紧跟在它所说明的名词后面，而是被别的词隔开。例如：HegotthenewsfromMarythatthesportsmeetingwasputoff.3.同位语从句与定语从句的区别(1)定语从句中的that既代替先行词，同时可以在从句中作某个成分（主语或宾语），而同位语从句中的that是连词，只起连接主句与从句的作用，不充当句中任何成分。(2)定语从句是形容词性的，其功能是修饰先行词，对先行词加以限定，描述定的性质或特征；同位语从句是名词性的，其功能是对名词进行补充说明。例如：1)ThenewsthathetoldmeisthatTomwouldgoabroadnextyear.（他告诉我的消息是汤姆明年将出国。）（第一个that引导的从句是定语从句，that在从句中作宾语）2)ThenewsthatTomwouldgoabroadistoldbyhim.（汤姆将出国的消息是他讲的。）（同位语从句，that在句中不作任何成分）练习：判断划线部分属哪种名词性从句1.It is certain that she will do well in her exam.2.The foreigner expressed his hope that he was going to visit the Great Wall again.3.She walked up to where he stood.4.We consider it necessary that he should improve his pronunciation.5.This is where our problem lies.6.W