沖刺高考英語語法講解與練習(xí) 名詞性從句

名詞性從句主語從句、表語從句、賓語從句、同位語從句，在整個(gè)句子中所起的作用，相當(dāng)于一個(gè)名詞。因此，這四種從句通稱為名詞性從句。引導(dǎo)名詞性從句的連接詞可分為三類：連接詞：that,whether,if（不充當(dāng)從句的任何成分）連接代詞：what,whatever,who,whoever,whom,whose,which.連接副詞：when,where,how,why主語從句一、主語從句的概念與類型主語從句在復(fù)合句中作主句的主語,引導(dǎo)主語從句的詞有從屬連詞that,whether以及連接代詞who,what,which,whoever,whatever,whichever和連接副詞when,where,why,how等.例如:Thatshewaschosenmadeusveryhappy.她當(dāng)選了使我們很高興.Whatcausedtheaccidentisacompletemystery.是什么導(dǎo)致了這次事故還完全是一個(gè)謎.Whethershewillcomeornotisstillaquestion.她是否來還是一個(gè)問題.Whichteamwillwinthematchisstillunknown.哪個(gè)隊(duì)會(huì)贏得這場(chǎng)比賽還不知道.Whoevercomestothepartywillreceiveapresent.參加聚會(huì)的每一個(gè)人都將收到一份禮物.Whentheywillstarthasnotbeendecidedyet.他們何時(shí)出發(fā)還沒決定.注意:上述例句中的主語從句都是放在句首,但有時(shí)為了使句子結(jié)構(gòu)平衡,避免"頭重腳輕",常用it作形式主語,而把從句放在后面.例如:Itisapitythatshehasmadesuchamistake.她犯了這樣一個(gè)錯(cuò)誤,真是遺憾.Itdependsontheclimatewhethertheyaregoingshoppingtoday.他們是否今天去購物還得看天氣情況.這樣就構(gòu)成了下面一些常用句型:1)Itis+adj./n.+從句Itisapity/shamethat...遺憾的是……Itispossiblethat...很可能……Itisunlikelythat...不可能……2)It+不及物動(dòng)詞+從句Itseems/appearsthat...似乎……Ithappenedthat...碰巧……3)It+be+過去分詞+從句Itissaidthat...據(jù)說……Itisknowntoallthat...眾所周知……Itisreportedthat...據(jù)報(bào)道……Itisbelievedthat...據(jù)信……;人們相信……Itissuggestedthat...有人建議……Itmustbepointedoutthat...必須指出……Ithasbeenprovedthat...已證明…….例如:Itisbelievedthatatleastascoreofbuildingsweredamagedordestroyed.據(jù)信,至少有二十座樓房遭到破壞或徹底毀掉.Itissuggestedthatthemeetingshouldbeputoff.有人建議會(huì)議延期召開.It'sreportedthatthreepeoplewerekilledintheaccidentandfivewerehurtbadly.據(jù)報(bào)道,事故中三人喪生,五人重傷.ItisknowntoallthatTaiwanisaninseparablepartofChina.眾所周知,臺(tái)灣是中國不可分割的一部分.[鞏固練習(xí)]1.Does_______matterifhecan'tfinishthejobontime?A.thisB.thatC.heD.it2.Itworriedherabit_______herhairwasturninggrey.A.whichB.thatC.ifD.for3._______isafactthatEnglishisbeingacceptedasaninternationallanguage.A.ThereB.ThisC.ThatD.It二、學(xué)習(xí)主語從句應(yīng)該注意的幾個(gè)問題1)引導(dǎo)詞that與whatwhat既有引導(dǎo)主語從句的作用,同時(shí)又在從句中作句子成分(主語、賓語、表語等).這時(shí)what相當(dāng)于allthat/everythingthat...,常譯成"所……的(東西、事情、話等.)";而that只起連接作用,本身無實(shí)際意義,在從句中也不擔(dān)當(dāng)任何句子成分.但that引導(dǎo)的主語從句放在句首時(shí),不能省略that.例如:Whatisdonecan'tbeundone.(諺語)已成定局,無可挽回.Whatwecan'tgetseemsbetterthanwhatwehave.我們得不到的東西似乎比已得到的要好.Thatweshouldworkoutaplantodealwiththepresentserioussituationisimportant.我們應(yīng)該制定一項(xiàng)計(jì)劃來應(yīng)付目前嚴(yán)峻的形勢(shì),這一點(diǎn)非常重要.Thatanewteacherwillcometoteachusgeographyistrue.一位新老師將來教我們地理,這是真的.[鞏固練習(xí)]4._______whattheytoldmereallytrue?A.HasB.IsC.DoesD.Have5.Itmatterslittle_______amandies,but_______mattersmuchis_______helives.A.how;what;howB.how;it;howC.why;it;whyD.that;what;that6._______shecouldn'tunderstandwas_______fewerandfewerstudentsshowedinterestinherlessons.A.What;whyB.That;whatC.What;becauseD.Why;that7.Itisprettywellunderstood_______controlstheflowofcarbondioxideinandouttheatmospheretoday.A.thatB.whenC.whatD.how8._______fashiondiffersfromcountrytocountrymayreflecttheculturaldifferencesfromoneaspect.A.WhatB.ThatC.ThisD.Which9.-Whatmadeherparentssoangry?-_______shehadfailedintheexamination.A.AsB.BecauseC.SinceD.That2)引導(dǎo)詞if和whetherif和whether引導(dǎo)動(dòng)詞后的賓語從句時(shí)一般可通用,但介詞后的賓語從句、主語從句(放在句首時(shí))、表語從句常由whether引導(dǎo).例如:Whethershewillgohomeornotisunknown.她是否回家還不得而知.Whetherweshallraiseducksorgeeseremainstobedecided.我們是養(yǎng)鴨還是養(yǎng)鵝仍沒決定.=Itremainstobedecidedwhether/ifweshallraiseducksorgeese.但我們不能說Ifweshallraiseducksorgeeseremainstobedecided.[鞏固練習(xí)]10._______we'llgocampingtomorrowdependsontheweather.A.IfB.WhetherC.ThatD.Where3)其它引導(dǎo)詞連接代詞who,which,whom,whose有各自的意義,起連接作用,并在從句中充當(dāng)語、賓語、表語、定語等;連接副詞when,where,why,how等有各自的意義,起連接作用,并在從句中充當(dāng)狀語.[鞏固練習(xí)]11.-Doyouremember_______hecame?-Yes,Ido.Hecamebycar.A.howB.whenC.thatD.if12.Itwasamatterof_______wouldtaketheposition.A.whoB.whoseC.whomD.whomever13.-IdrovetoZhuhaifortheairshowlastweek.-Isthat_______youhadafewdaysoff?A.whyB.whenC.whatD.where14.Ireadaboutitinsomebookorother,doesitmatter_______itwas?A.whereB.whatC.howD.which三、語氣在Itisnecessary/natural/important/strange...+that-clause這類句型里,that所引導(dǎo)的主語從句中謂語動(dòng)詞用"should+原形",表虛似語氣.例如:Itisnecessarythattheproblemshouldbesettledatonce.這個(gè)問題必須馬上解決.It'sstrangethatheshouldhavegoneawaywithouttellingus.他竟然沒向我們說一聲就走了,真是奇怪.[鞏固練習(xí)]15.Itisnecessarythatacollegestudent_______atleastaforeignlanguage.A.mastersB.shouldmasterC.masteredD.willmaster四、以it作形式主語的主語從句與強(qiáng)調(diào)句型的區(qū)別"Itbe+adj./n.+that-clause"與強(qiáng)調(diào)句型均有Itbe...that...之類的語言標(biāo)志,但不同的是:①前者中的that從句是主語從句.若刪掉其中的Itbe和that,則剩余部分不論結(jié)構(gòu)還是語意都不能成為一個(gè)句子;但若將后者中的Itbe和that去掉,則剩余部分的結(jié)構(gòu)和語意仍能構(gòu)成一個(gè)完整的句子.②強(qiáng)調(diào)句型譯為漢語時(shí)可加上"正是……"或"就是……"之類的字眼,而主語從句則不可以.請(qǐng)比較下面兩個(gè)句子:ItissurprisingthatMaryshouldhavewonfirstplace.令人驚奇的是瑪莉竟然獲得了第一名.ItisMarythathaswonfirstplace.正是瑪莉得了第一名.第一句話中的It是形式主語,that引導(dǎo)的是主語從句.句中的Itis和that無法刪除,一旦刪除句子就不成立.第二句是強(qiáng)調(diào)句型,其中的Itis和that可以去掉,因?yàn)闆]有Itis和that句子仍然很通順.Key:1-5DBDBA6-10ACBDB11-15AAADB2.賓語從句名詞句用作賓語的從句叫賓語從句。引導(dǎo)賓語從句的關(guān)聯(lián)詞與引導(dǎo)主語從句表語從句的關(guān)聯(lián)詞大致一樣，在句中可以作謂語動(dòng)詞或介詞及非謂語動(dòng)詞的賓語。1.由連接詞that引導(dǎo)的賓語從句由連接詞that引導(dǎo)賓語從句時(shí)，that在句中不擔(dān)任任何成分，在口語或非正式的文體中常被省去，但如從句是并列句時(shí),第二個(gè)分句前的that不可省。例如：HehastoldmethathewillgotoShanghaitomorrow.他已經(jīng)告訴我他明天要去上海。Wemustneverthink(that)wearegoodineverythingwhileothersaregoodinnothing.我們決不能認(rèn)為自己什么都好，別人什么都不好。注意：在demand、order、suggest、decide、insist,desire,demand,request,command等表示要求、命令、建議、決定等意義的動(dòng)詞后，賓語從句常用“（should）+動(dòng)詞原形”。例如：Iinsistthatshe(should)doherworkalone.我堅(jiān)持要她自己工作。Thecommanderorderedthattroops(should)setoffatonce.司令員命令部隊(duì)馬上出發(fā)。2.用who，whom,which,whose,what,when,where,why,how,whoever,whatever,whichever等關(guān)聯(lián)詞引導(dǎo)的賓語從句相當(dāng)于特殊疑問句，應(yīng)注意句子語序要用陳述語序。例如：Iwanttoknowwhathehastoldyou.我想知道他告訴了你什么。Shealwaysthinksofhowshecanworkwell.她總是在想怎樣能把工作做好。Shewillgivewhoeverneedshelpawarmsupport.凡需要幫助的人，她都會(huì)給予熱情的支持。3.用whether或if引導(dǎo)的賓語從句，其主語和謂語的順序也不能顛倒，仍保持陳述句語序。此外，whether與if在作“是否”的意思講時(shí)在下列情況下一般只能用whether，不用if：a.引導(dǎo)主語從句并在句首時(shí)；b.引導(dǎo)表語從句時(shí)；c.引導(dǎo)從句作介詞賓語時(shí)；d.從句后有“ornot”時(shí)；e.后接動(dòng)詞不定式時(shí)。例如：Whetherthereislifeonthemoonisaninterestingquestion.月球上有沒有生命是個(gè)有趣的問題。Thequestioniswhethersheshouldhavealowopinionofthetest?Everythingdependsonwhetherwehaveenoughmoney.一切要看我們是否有足夠的錢。Iwonderwhetherhewillcomeornot.我想知道他來還是不來。Canyoutellmewhethertogoortostay?你能否告訴我是去還是留？4.注意賓語從句中的時(shí)態(tài)呼應(yīng)，當(dāng)主句動(dòng)詞是現(xiàn)在時(shí)，從句根據(jù)自身的句子情況，而使用不同時(shí)態(tài)。例如：hestudiesEnglisheveryday.（從句用一般現(xiàn)在時(shí)）hestudiedEnglishlastterm.（從句用一般過去時(shí)）Iknow(that)hewillstudyEnglishnextyear.（從句用一般將來時(shí)）hehasstudiedEnglishsince1998.（從句用現(xiàn)在完成時(shí)）當(dāng)主句動(dòng)詞是過去時(shí)態(tài)（could,would除外），從句則要用相應(yīng)的過去時(shí)態(tài)，如一般過去時(shí)，過去進(jìn)行時(shí)，過去將來時(shí)等；當(dāng)從句表示的是客觀真理，科學(xué)原理，自然現(xiàn)象，則從句仍用現(xiàn)在時(shí)態(tài)。例如：TheteachertoldusthatTomhadleftusforAmerica．5.think,believe,imagine,suppose等等動(dòng)詞引起的否定性賓語從句中，要把上述主句中的動(dòng)詞變?yōu)榉穸ㄊ?。即將從句中的否定形式移到主句中。例如：Wedon’tthinkyouarehere.我們認(rèn)為你不在這。Idon’tbelievehewilldoso.我相信他不會(huì)這樣做。3.表語從句在句中作表語的從句叫表語從句。引導(dǎo)表語從句的關(guān)聯(lián)詞與引導(dǎo)主語從句的關(guān)聯(lián)詞大致一樣，表語從句位于連系動(dòng)詞后，有時(shí)用asif引導(dǎo)。其基本結(jié)構(gòu)為：主語+系動(dòng)詞+that從句。（一）表語從句的引導(dǎo)詞引導(dǎo)表語從句的詞有連詞that,whether，連接代詞和連接副詞，關(guān)系代詞型what，以及asif,asthough,because等連詞。1.由that引導(dǎo)Thefactisthathedoesn’treallytry.事實(shí)是他沒有做真正的努力。ThetroubleisthatIhavelosthisaddress.麻煩的是我把他的地址丟了。Mysuggestionisthatweshouldtellhim.我的建議是我們應(yīng)該告訴他。Hissolerequirementwas(is)thatthesystemwork.他唯一的要求是這個(gè)制度能起作用。Myideaisthatweshouldstartmakingpreparationsrightnow.我的意見是我們馬上就開始做準(zhǔn)備工作。2.由whether引導(dǎo)Thequestioniswhetherthefilmisworthseeing.問題是這部電影是否值得看。【注意】whether可引導(dǎo)表語從句，但與之同義的if卻通常不用于引導(dǎo)表語從句。3.由連接代詞引導(dǎo)YouarenotwhoIthoughtyouwere.你已不是我過去所想像的人。Theproblemiswhowecangettoreplaceher.問題是我們能找到誰去替換她呢。Thequestioniswho(m)weshouldtrust.問題是我們應(yīng)當(dāng)相信誰。WhatIwanttoknowiswhichroadweshouldtake.我想知道的是我們應(yīng)走哪條路。4.由連接副詞引導(dǎo)Theproblemishowwecanfindhim.問題是我們?nèi)绾握业剿?。ThatwaswhenIwasfifteen.這是我15歲時(shí)發(fā)生的事。That’swhereIfirstmether.那就是我第一次遇見她的地方。That’swhyhedidn’tcome.這就是他沒有來的緣故。That’swhyIobjecttotheplan.這就是我反對(duì)這個(gè)計(jì)劃的原因。That’swhereyouarewrong.這就是你不對(duì)的地方。5.由關(guān)系代詞型what引導(dǎo)That’swhatIwanttostress.這是我想強(qiáng)調(diào)的。That’swhatweareherefor.我們來這里就為了這個(gè)。Fameandpersonalgainiswhatthey’reafter.他們追求的是名利。Heisnolongerwhathewas.他已經(jīng)不是以前的他了。6.由asif/asthough引導(dǎo)Itisn’tasifyouweregoingawayforever.又不是你離開不回來了。NowitwasasthoughshehadknownMillieforyears.現(xiàn)在好像她認(rèn)識(shí)米莉已有好多年了似的。Itisnotasthoughwewerepoor.又不是我們家里窮。7.由because引導(dǎo)ItisbecauseIloveyoutoomuch.那是因?yàn)槲姨珢勰懔恕hat’sbecauseyoucan’tappreciatemusic.這是因?yàn)槟悴荒苄蕾p音樂。IfI’mabitsleepy,it’sbecauseIwasupallnight.如果我有點(diǎn)困，是因?yàn)橐灰箾]睡。It'sbecauseIpassedaslipofpaperforJohntoHeleninclass.這是因?yàn)槲以谏险n中替約翰傳紙條給海倫?！咀⒁狻縝ecause可引導(dǎo)表語從句，但與之同義的since,as,for等也不用于引導(dǎo)表語從句。（二）、連詞that的省略問題引導(dǎo)表語從句的that通常不省略，但在口語或非正式文體中有時(shí)也可省略：Myideais(that)weshoulddoitrightaway.我的意見是我們應(yīng)該馬上干。Thetroubleis(that)heisill.糟糕的是他病了。4.同位語從句同位語從句說明其前面的名詞的具體內(nèi)容。同位語從句通常由that引導(dǎo)，可用于同位語從句的名詞有advice、demand、doubt、fact、hope、idea、information、message、news、order、problem、promise、question、request、suggestion、truth、wish、word等。）一）、同位語從句的引導(dǎo)詞引導(dǎo)同位語從句的詞語通常有連詞that，whether，連接代詞和連接副詞等。1.由that引導(dǎo)Weheardthenewsthatourteamhadwon.我們聽到消息說我們隊(duì)贏了。Theywereworriedoverthefactthatyouweresick.他們?yōu)槟闵“l(fā)愁。Thenewsthatwearehavingaholidaytomorrowisnottrue.明天放假的消息不實(shí)。I’vecometotheconclusionthatitwasunwisetodothat.我得出結(jié)論這樣做是不明智的。Thefactthatthemoneyhasgonedoesnotmeanitwasstolen.那筆錢不見了這一事實(shí)并不意味著是被偷了。HereferredtoCopernicus’statementthattheearthmovesroundthesun.他提到了哥白尼關(guān)于地球繞太陽轉(zhuǎn)的說法?！咀⒁?】在某些名詞(如demand,wish,suggestion,resolution等)后面的同位語從句要用虛擬語氣。如：Theywerefacedwiththedemandthatthistaxbeabolished.他們面對(duì)廢除這個(gè)稅的要求。Theyexpressedthewishthatsheaccepttheaward.他們表示希望她接受這筆獎(jiǎng)金。TherewasasuggestionthatBrownshouldbedroppedfromtheteam.有一項(xiàng)建議是布朗應(yīng)該離隊(duì)。Thesuggestionthatthenewrulebeadoptedcamefromthechairman.采納新規(guī)則的建議是主席提出的。Theresolutionthatwomenbeallowedtojointhesocietywascarried.允許婦女參加這個(gè)協(xié)會(huì)的決議通過了。Icanunderstandtheireagernessthatyoushouldbethemainspeaker.我理解他們希望你作主要發(fā)言人的殷切心情?！咀⒁?】引導(dǎo)同位語從句的連詞that通常不省略，但在非正式文體中也可以省去。如：HegabbedhissuitcaseandgavetheimpressionhewasboardingtheTokyoplane.他拿起了手提箱，給人的印象是他要登上飛往東京的飛機(jī)了。2.由whether引導(dǎo)Thereissomedoubtwhetherhewillcome.他是否會(huì)來還不一定。Answermyquestionwhetheryouarecoming.你回答我的問題：你來不來。Thequestionwhetheritisrightorwrongdependsontheresult.這個(gè)是對(duì)還是錯(cuò)要看結(jié)果。Wearenotinvestigatingthequestionwhetherheistrustworthy.我們不是在調(diào)查他是否可以信任的問題?！咀⒁狻縲hether可引導(dǎo)同位語從句，但if不能引導(dǎo)同位語從句。3.由連接代詞引導(dǎo)Haveyouanyideawhattimeitstarts?你知道什么時(shí)候開始嗎?From1985-90Iwasaninstructorattheregionalpartyheadquarters.AfterthatIwentbacktoworkinafactory.ThenIhadnoideawhatacasinowas.從1985年到1990年我是地方黨部的教員。隨后我回到一家工廠工作。當(dāng)時(shí)我不知道賭場(chǎng)是什么樣的地方。4.由連接副詞引導(dǎo)Ihavenoideawhenhewillcomeback.我不知道他什么時(shí)候回來。Itisaquestionhowhedidit.那是一個(gè)他如何做的問題。Hehadnoideawhysheleft.他不知道她為什么離開。YouhavenoideahowworriedIwas!你不知道我多著急!（二）、關(guān)于分離同位語從句有時(shí)同位語從句可以和同位的名詞分開。如：Thestorygoesthathebeatshiswife.傳說他打老婆。Thenewsgotaboutthathehadwonacarinthelottery.消息傳開說他中彩得了一輛汽車。Therumourspreadthatanewschoolwouldbebuilthere.謠傳這里要蓋一所新學(xué)校。ReporthasitthattheSmithsareleavingtown.有傳言說史密斯一家要離開這座城市。Thethoughtcametohimthatmaybetheenemyhadfledthecity.他想到可能敵人已逃離這座城市。Theordersooncamethatallcitizensshouldevacuatethevillage.不久命令下來，所有居民都必須撤出村子。(二.名詞性從句中的虛擬語氣1.主語從句中的虛擬語氣主語從句中的虛擬語氣主要取決于某些形容詞和過去分詞，用來表示建議、命令、要求、驚異和失望等。其形式為：（should）+動(dòng)詞原形。常這樣用的形容詞有：appropriate適當(dāng)?shù)腶dvisable適當(dāng)?shù)?，合理的better較好的desirable理想的essential精華的imperative迫切的important重要的insistent堅(jiān)持的natural自然的necessary必要的preferable優(yōu)越的，較好的strange奇怪的urgent緊迫的vital極其重要的過去分詞有：desired,demanded,ordered,requested,suggested,recommended,required等。例如：Itisessentialthatyou(should)winthevoters’hearts.贏得選民的心是絕對(duì)必要的。Itwassuggestedthathe(should)jointheclubactivities.有人提議他應(yīng)該參加俱樂部的活動(dòng)。2.表語從句和同位語從句中的虛擬語氣在表示建議、命令、主張、目的和愿望等名詞后面的表語從句和同位語從句中謂語動(dòng)詞要求使用虛擬語氣。其形式為：（should）+動(dòng)詞原形。常這樣用的名詞有：resolution決心，決議pray懇求decision決議motion提議suggestion建議preference選擇proposal提議advice勸告recommendation推薦desire愿望demand要求requirement要求order命令necessity必要性request要求idea主意、想法例如：Hegaveordersthattheguests(should)behospitablyentertained.他下令熱情款待這些客人。Hisproposalisthatwe(should)getridofthebadhabits.他提議我們應(yīng)該擯棄這些不良習(xí)性。3.賓語從句中的虛擬語氣1）某些動(dòng)詞后所接賓語從句中的謂語動(dòng)詞要求用虛擬語氣，用來表示建議、命令和要求等。其形式為：（should）+動(dòng)詞原形。常這樣用的動(dòng)詞有：ask要求advise勸告determine決定decide決定command命令insist堅(jiān)持intend打算move提議prefer寧愿propose提議order命令recommend推薦request要求require要求suggest建議urge主張demand要求desire渴望direct命令例如：Heinsistedthatthemeetingbeputoff.他要求推遲那個(gè)會(huì)議。Theyproposedthatalltheplansshouldbediscussedatthemeeting.他們建議所有的計(jì)劃都應(yīng)該在會(huì)上討論。2）在以it為形式賓語的復(fù)合賓語從句中也可以用虛擬語氣，其形式為：（should）+動(dòng)詞原形。這一句型中使用的形容詞（賓補(bǔ)）與主語從句中的虛擬語氣所使用的形容詞相同。例如：Wethinkitadvisablethathe(should)thinkdeeplybeforeacting.我們認(rèn)為他在行動(dòng)之前好好考慮一下才是明智的。3）wish后面所跟的賓語從句中的虛擬語氣表示某種不能實(shí)現(xiàn)的愿望。其主要形式有三種：表示對(duì)現(xiàn)在情況的虛擬：wish+主語+動(dòng)詞過去式或were表示對(duì)過去情況的虛擬：wish+主語+had+過去分詞表示對(duì)將來情況的虛擬：wish+主語+would+動(dòng)詞原形。例如：IwishIknewwhatwasgoingtohappen.但愿我能知道要發(fā)生什么事。Shewishedshehadstayedathome.她懊悔的是她當(dāng)時(shí)要是在家就好了。IwishIwererich.我恨不得我很有錢。注意：在表示對(duì)過去情況的虛擬時(shí)，有時(shí)也可以用下列形式：wish+主語+would（could）+have+過去分詞IwishIcouldhaveseenherlastnight.要是我昨天晚上能夠見到她那該多好。4.if條件句中的虛擬語氣形式1）if非真實(shí)條件句所表示的假設(shè)則是不可能或不大可能發(fā)生或?qū)崿F(xiàn)的，句中的主句與從句都用虛擬語氣。在if非真實(shí)虛擬條件句中，主句和從句謂語動(dòng)詞主要有下面幾種形式：假設(shè)類型條件從句謂語動(dòng)詞形式主句謂語動(dòng)詞形式與現(xiàn)在事實(shí)相反動(dòng)詞過去時(shí)（be用were）Should（would，could，might）+動(dòng)詞原形與過去事實(shí)相反Had+過去分詞Should（would，could,might）+have+過去分詞與將來事實(shí)可能相反動(dòng)詞過去時(shí)（should+動(dòng)詞原形，wereto+動(dòng)詞原形）Should（would，could，might）+動(dòng)詞原形Iftherewerenogravity,weshouldnotbeabletowalk.假如沒有引力，我們就不可能行走。Iwouldn’thaveknownwhatthesewereforifIhadn’tbeentold.假如別人不告訴我，我就不知道這些東西是干什么的了。2）正式文體中，有時(shí)可把虛擬條件句中的連詞if省去，而將were，had,should等助動(dòng)詞（不包括行為動(dòng)詞）提到主語前面。如果句中沒有were，had或should時(shí)，既不能省略if，也不能倒裝。例如：WereItomeethimtomorrow(=IfIweretomethimtomorrow),Ishouldaskhimaboutit.要是我明天見到他，我就會(huì)問他這件事的。HadIhadthemoneylastyear(=IfIhadhadthemoneylastyear),Iwouldhaveboughtthehouse.如果我去年有了這筆錢，我就買那所房子了。Shouldtherebeanytroublewiththeboiler,theautomaticcontrollingunitwouldcutoffthefueloilsupply.假如鍋爐出問題的話，自控裝置會(huì)自動(dòng)切斷燃油的供給。3）通常情況下，在非真實(shí)條件句中主句和從句的謂語動(dòng)詞所指時(shí)間是一致的，但有時(shí)也可能指不同的時(shí)間，這時(shí)要根據(jù)上下文的意思采用不同的謂語動(dòng)詞形式。例如：IfIwereyou,Iwouldhavetakenhisadvice.我要是你，我就采納了他的建議。（從句指現(xiàn)在，主句指過去）Iftheweatherhadbeenmorefavorable,thecropwouldbegrowingstillbetter.如果氣候更適宜一些，莊稼會(huì)長得更好。（從句指過去，主句指現(xiàn)在）5.含蓄虛擬條件句1）有時(shí)假設(shè)的情況并不以條件從句形式表示出來，而是通過一個(gè)介詞短語或其他方式表示。常用的詞或短語有：without,butfor,butthat,otherwise,or,but等。例如：Withoutyourhelp(=Ifwehadnothadyourhelp),wecouldnothavesucceeded.要是沒有你的幫助，我們就不會(huì)成功的。Butforelectricity(=Iftherewerenoelectricity),therewouldbenomodernindustry.要是沒有電，就不會(huì)有現(xiàn)代工業(yè)。Hewashavingameeting;otherwisehewouldhavecomeovertohelpus.他當(dāng)時(shí)正與他的學(xué)生進(jìn)行討論，否則的話他就來幫我們了。Hefeltverytiredyesterday,orhewouldhaveattendedtheparty.他昨天很累，不然他就參加那個(gè)聚會(huì)了。2）在某些暗含虛擬條件的簡單句中，虛擬語氣可通過上下文表現(xiàn)出來。謂語動(dòng)詞用should/wouldbe形式和should/wouldhavebeen虛擬形式。例如：Anymeninhispositionwouldhavedonelikethat.任何人處在他的位置都會(huì)那么做的。Youshould(oughtto)havecomeearlier.你本應(yīng)來得早點(diǎn)。6.其他句型中的虛擬語氣1）在wouldrather,wouldsooner,wouldjustassoon,mightaswell和wouldprefer等后面所跟的從句中，也可以用虛擬語氣，表示愿望，意為“寧愿、但愿”。其形式為：①“wouldrather(wouldsooner…)+主語+謂語動(dòng)詞過去式”表示現(xiàn)在或?qū)淼那闆r。②“wouldrather(wouldsooner)+主語+動(dòng)詞過去完成式”表示過去的情況。例如：I’dratherhedidn’tgonow.要是他現(xiàn)在不走就好了I’djustassoonyouhadbeenhereyesterday.要是你昨天在這里就好了。2）在句型“Itis(high/about)time…”后面也可以跟虛擬語氣，從句中常用過去式。有時(shí)也用“（should）+動(dòng)詞原形”，意為“該是……的時(shí)候了”。例如：Itistimethattheboy(should)gotoschool.這個(gè)小孩該上學(xué)了。Itishightime(that)theweatherimproved.天氣真該好起來了。3）在“ifonly”引起的感嘆句中也要求用虛擬語氣，表示愿望。形式為：①用過去時(shí)或“would/could+動(dòng)詞原形”表示與現(xiàn)在或未來事實(shí)相反的愿望。②過去完成時(shí)表示與過去事實(shí)相反的愿望。例如：Ifonlyyouwouldlistentoouradvice.要是你聽我們的建議就好了。IfonlyIhadnotbeenbusylastweek!要是上周我不忙該多好??！Ifonlyshecouldmarryme.但愿她能嫁給我。注：ifonly也可以用于虛擬條件句中。例如：IfonlyIhadmoremoney,Icouldbuyacar.要是我有更多的錢，我就可以買輛車了。4）連接詞“incase,lest,forfearthat”可以用來引導(dǎo)虛擬語氣。其形式通常為：“…lest(incase,forfearthat)+主語+should+動(dòng)詞原形”。Lest,forfearthat句中的should可以省去，incase句中的should通常不省去，但是incase句中可以不用虛擬語氣，而用陳述語氣。Lest,forfearthat后面也可以接其他形式。例如：Hetookhiscoatwithhimincaseitshouldrain.他帶著雨衣以防下雨。IwillnotmakeanoiseforfearthatI(should/might)disturbyou.我不會(huì)做聲的，以免打擾你。Caremustbetakeninusingthismethodlestoverflow(should)occur.在使用這以方法的時(shí)候要謹(jǐn)慎小心，以免發(fā)生溢流現(xiàn)象。同位語從句與定語從句的區(qū)別1．意義的不同同位語從句是用于說明所修飾名詞的具體內(nèi)容的，它與被修飾詞語通?？梢詣澋忍?hào)；而定語從句是限制所修飾名詞的，它的作用是將所修飾的名詞與其他類似的東西區(qū)別開來：Wearegladatthenewsthathewillcome.聽到他要來這個(gè)消息我們很高興。(news的內(nèi)容就是thathewillcome，故that引導(dǎo)的是同位語從句)Wearegladatthenewsthathetoldus.聽到他告訴我們的這個(gè)消息我們很高興。(that從句是限制thenews的內(nèi)容的，即我們高興只是因?yàn)樗嬖V的這個(gè)news而不是其他的news，故that從句為定語從句)2.引導(dǎo)詞的不同what,how,if,whatever等可引導(dǎo)名詞性從句，但不引導(dǎo)定語從句。3.引導(dǎo)詞的功能上的不同that引導(dǎo)同位語從句時(shí)，它不充當(dāng)句子成分，而引導(dǎo)定語從句時(shí)，它作為關(guān)系代詞，要么充當(dāng)定語從句的主語，要么充當(dāng)定語從句的賓語。如上例thathetoldus中的that就充當(dāng)told的賓語。4.被修飾詞語的區(qū)別同位語從句所修飾的名詞比較有限，通常有hope,wish,idea,news,fact,promise,opinion,suggestion,truth等，而定語從句所修飾的名詞則非常廣泛。另外，when和where引導(dǎo)定語從句時(shí)，通常只修飾表示時(shí)間和地點(diǎn)的名詞，而它們引導(dǎo)同位語從句時(shí)卻不一定；又如why引導(dǎo)定語從句，它通常只修飾名詞thereason，而它引導(dǎo)同位語從句時(shí)則不一定：Ihavenoideawhentheywillcome.我不知道他們什么時(shí)候來。(同位語從句)I’llneverforgetthedayswhenIlivedthere..我永遠(yuǎn)不會(huì)忘記我住在那兒的日子。(定語從句)Wedon’tunderstandtheproblemwhythisisthebestchoice.我們不明白這個(gè)問題，為什么這是最好的選擇。(同位語從句)Thereasonwhyhedidn’tcometothemeetingisthatheisill.他未能來開會(huì)，原因是他生病了。(定語從句)Theprimaryreasonwasskepticismthatarailroadbuiltthroughsochallengingandthinlysettledastretchofdesert,mountain,andsemiaridplaincouldpayaprofit.同位語從句主句:Theprimaryreasonwasskepticism.that從句做skepticism的同位語，具體說明skepticism.that從句主干arailroadcouldpayaprofit.其他的都是用來修飾railroad...過去分詞短語做后置定語修飾railroad.常見的同位語從句先行詞是news，idea，fact，promise，question，doubt，thought，hope，message，suggestion，words（消息），possibility等。這些都是抽象名詞，你的這個(gè)例子中skepticism,懷疑態(tài)度也是抽象名詞。同位語從句的特點(diǎn)是，你可以去掉先行詞，句子仍然成立，沒有語法錯(cuò)誤。這里Theprimaryreasonwasthatarailroadbuiltthroughsochallengingandthinlysettledastretchofdesert,mountain,andsemiaridplaincouldpayaprofit.無錯(cuò)誤。所以原句是同位語從句。名詞性從句專項(xiàng)練習(xí)100題1.Hissuccesswasbecauseof________hehadbeenworkinghard.A.thatB.thefactwhichC.thefactthatD.thefact2.“IsMaryfromNewYorkCity”“Idon'tknow_______.”A.fromwhatcitydoesshecomefromB.fromwhatcityshecomeC.whatcitydoesshecomefromD.whatcityshecomesfrom3.________makesmistakesmustcorrectthem.A.WhatB.ThatC.WhoeverD.Whatever4.ThereasonwhyIdidn'tgotoShanghaiwas________anewjob.A.becauseIgotB.becauseofgettingC.IgotD.thatIgot5.Itworriedherabit____herhairwasturninggrey.A.whileB.thatC.ifD.for6.Henrykilledthedog.I'llaskhimwhy________.A.didhedothatB.hedidthatC.hedidD.hehasdoneso7.HaveyouseenHenrylatelyMybosswantstoknow________.A.howheisgettingalongB.howishegettingalongC.whatheisgettingalongD.whatishegettingalong8.Itisgenerallyconsideredunwisetogiveachild____heorshewants.A.howeverB.whateverC.whicheverD.whenever9.Heaskedme________withme.A.whatisthetroubleB.whatwrongwasC.whatwasthematterD.whattroubleitis10.Iamsure________hesaidistrue.A.thatB.aboutthatC.ofthatD.thatwhat11.Whenandwhyhecamehere________yet.A.isnotknownB.arenotknownC.hasnotknownD.havenotbee12.Iwonderhowmuch________.A.doesthewatchcostB.didthewatchcostC.thewatchcostedD.thewatchcosts13.Maryis________someonemightrecognizeher.A.afraidofB.afraidaboutC.afraidthatD.afraidfor14.________isnoreasonfordismissingher.A.BecauseshewasafewminuteslateB.OwingtoafewminuteslateC.ThefactthatshewasafewminuteslateD.Beingafewminuteslate15.Theycametotheconclusion________byacomputer.A.thatnotallthingscanbedoneB.becauseofnotallthingsbedoneC.beingnotallthingscanbedoneD.becausenotallthingscanbedone16.Whytheexplosionoccurredwas________thelaboratoryattendanthadbeencareless.A.forB.becauseC.sinceD.that17.Idon'tdoubt________he'llcome.A.thatB.ifC.whatD.whether18.—“Whydidyougotothewrongclass,Mr.Wang”—“Well,Iforget_______Iwassupposedtogoto.”A.whichtheroomB.whichroomC.whatwastheroomD.whatroomwasit19.Outputisnowsixtimes________itwasbeforeliberation.A.thatB.whichC.whatD.ofwhich20.Mary:Helenisamerewasherwoman,yetshe'snowbuyingabighouse.Carol:Yes.Becauseshe'salwayssaved________.A.whatlittlesheearnsB.howlittlesheearnsC.forlittlesheearnsD.withlittlesheearns21.______surprisedmemostwas______suchalittleboyofsevencouldplaytheviolinsowell.A.That…whatB.What…thatC.That…whichD.What…which22.Wegavehim________helpwecould.A.whichB.whatC.thatD.this23.Sheispleasedwithwhatyouhavegivenhimand________youhavetoldhim.A.thatB.whichC.allwhatD.allthat24.Excusemewouldyoupleasetellme________A.whenthesportsmeetistakenplaceB.whenisthesportsmeetgoingtobeheldC.whenisthesportsmeettobeginD.whenthesportsmeetistotakeplace25.Doyouhappentoknow________A.whatsizeshoeshewearsB.howbigshoeshewearsC.whatisthesizeofhisshoesD.whatnumbershoesarehis26.Thisbookwillshowyou________canbeusedinothercontexts.A.howyouhaveobservedB.howwhatyouhaveobservedC.thatyouhaveobservedD.howthatyouhaveobserved27.Wheredoyouthink________A.hashegoneB.hashebeenC.he'sgoneD.washe28.Doyouknow________A.howmanypopulationsthereareintheworldB.howmuchpopulationthereisintheworldC.howmanythepopulationoftheworldisD.whatthepopulationoftheworldis29.Wouldyougoandsee________outsideA.whattotakeplaceB.whatTomhashappenedC.whatishappeningD.whatthematterhadbeen30.Thesubjectof"WhatisinterestingisthatIdonotevenknowhim."is_______.A.whatB.interestingC.WhatisinterestingD.I31.________IthinkheisCharles.A.WhodoyouthinkheisB.DoyouthinkwhoheisC.WhomdoyouthinkheisD.Doyouthinkwhoheis32.Hedidn'tknowwhichroom________.A.theylivedB.theylivedinC.didtheyliveD.didtheylivein33.Thelittleboyate________hismothergavehim.A.thatB.whichC.whateverD.nomatterwhat34.Thecityisnolonger________.A.whatitisB.thatitusedtobeC.whichitwasD.whatitusedtobe35.Myparentsused________theyhadtogetanewcarforme.A.whichB.thatC.whatD.allwhat36.________wegoswimmingeveryday________usalotofgood.A.If…doB.That…doC.If…doesD.That…does37.________wastheidea_______thewifethoughtofA.What…thatB.That…whatC.How…whyD.Why…h(huán)ow38._______didhetellhiswife________hewishedtodoA.That…whatB.What…thatC.Where…whichD.Which…where39.Oneofthemenheldtheview________thebooksaidwasright.A.whatthatB.thatwhatC.thatwhichD.whichthat40.Ihavenoidea________ornothehasfinishedthework.A.ifB.thatC.whetherD.which41.—“Doyouknow________”—“Hisfatherisadoctor.”A.whatishisfatherB.whoishisfatherC.whathisfatherisD.whohisfatheris42.Isthis________wemeteachothertwoyearsagoA.placeB.placeinwhichC.whereD.placewhich43.It________Bobdrivesbadly.A.thinksthatB.isthoughtwhatC.thoughtthatD.isthoughtthat44.Weallknowthetruth________thereareair,waterandsunlighttherearelivingthings.A.whereB.whereverC.thatD.thatwherever45.Theydiscussed________theycouldsettletheproblemwithoutothers'help.A.ifB.thatC.whatD.whether46.Sheasked________.A.whatIwasdoingwhensherangmeupB.whatwasIdoingwhensherangmeupC.whensherangmeupwhatIwasdoingD.whendidsheringmeupwhatIwasdoing47.—MayIborrowthering—Youcantake_______youlike.A.nomatterwhatB.whichC.whicheverD.that48.Hesaidthathewasfondof________.A.whatbeautifulisB.whatisbeautifulC.beautifuliswhatD.whatitisbeautiful49.Heinsistedthathe________ingoodhealthand_______toworkthere.A.was,besentB.is,is