it的用法归纳

•Neverbeafraidofgrammar•Collectsomeexamples;•Watchthemverycarefully;•Findoutsomethingincommon;•Trytousetherules----practise.it用法完全归纳一、it作人称代词的用法1.指事物作为人称代词，it可以除人以外的一切事物或动物。如：Idroppedmywatchanditbroke.我把手表掉在地上摔坏了。It’shardwork,butIenjoyit.工作很辛苦，可是我乐意干。“Whereisthedog?”“It’sinthebedroom.”“狗在哪?”“在卧室里”。2.指人it指人主要用于指不性别不明的婴儿或用于确认某人的身份。如：Isitaboyoragirl?是男孩还是女孩?Thereisaknockonthedoor.Itmustbethepostman.有人在敲门，一定是邮递员。【说明】在答语中，常用来指本人，如说It’sme。3.代替某些代词代词it还可用于代替指示代词this,that以及复合不定代词something,anything,nothing等。如：“What’sthis?”“It’sanewmachine.”“这是什么?”“是一种新机器”。Nothingiswrong,isit?没出什么问题，是吗?二、it作非人称代词的用法1.基本用法it作非人称代词的用法，主要用于指时间、距离、价值、天气、气候及温度等自然现象。如：It’stoolatetogotherenow.现在去那儿已经太迟了。Itrainedalldayyesterday.昨天下了一天的雨。Itcangetveryhothere.这里有时会很热。2.用于某些句型It’stimeforsth.该做某事了。It’stimetodosth.该做某事的时候了。It’stimeforsbtodosth.某人该干某事了。It’s(about/high)time+that-从句.某人该做某事了。(从句谓语用过去式，有时也用“should+动词原形”)It’sfirst(second)time+that-从句.某人第几次干某事。(从句谓语用现在完成时)It’s+时间段+since-从句.自从……有一段时间了。It’s+时间段+before-从句.过多长的时间才……三、it用作形式主语1.基本用法当不定式、动名词、从句等复杂成分用作句子主语时，为保持句子平衡，通常把真正的主语放在句末，而在句首使用形式主语it。如：It’sveryimportanttorememberthis.记住这一点很重要。It’shardworkclimbingmountains.爬山是费劲的事。It’sunknownwhenhewillcome.他什么时候来还不知道。2.用作形式主语的的重要句型(1)It+be+adj.for(of)sbtodosth某人做某事……Itishardforhimtomakeuphismind.他很难下定决心。Itwasfoolishofhertosaysuchathing.她说那样的话，真是太蠢了。【说明】介词of与for的区别是：of用于指某人的性格、属性、特征等，介词for表示对象，意为“对……来说”(from)。(2)Ittakessb+时间段+todosth.某人做某事花了……时间Ittakesyearstomasteranewlanguage.要花多年的时间才能掌握一门新的语言。【说明】此句型可以有以下多变种变体：Ittookmeanhourtowritetheletter.=Thelettertookmeanhour(towrite).=Itookanhourtowritetheletter.我写这封信花了一个小时。(3)Itisuptosbtodosth.该由某人做某事It’suptoyoutotomakethechoice.得由你来作选择。(4)itlook(seem,appear,happen,occur)that[asif]…似乎……Itseemedasthoughhedidn’trecognizeme.他似乎没认出我来。IthappenedthatIwasoutwhenhecalled.他打电话时我碰巧不在家。(5)Ifitwerenotfor…/Ifithadn’tbeenfor…若不是因为……Ifitwerenotfortheirhelp,wecouldn’thavegotoverthedifficulties.要不是他们帮助，这些困难我们不克服不了的。四、it用作形式宾语1.基本用法当不定式、动名词、从句等复杂成分用作宾语且其后跟有宾语补足语时，通常会在宾语补足语前使用形式宾语，而将真正的宾语移至句末。其基本结构为“动词+it+宾语补足语+不定式(动名词或从句)”。如：Ifinditdifficulttodothejobwell.我发现做好这件事不容易。Ithinkitbestthatyoushouldstayhere.我认为你最好住这儿。Wethinkitnousecomplaining.我们认为抱怨是没有用的。2.用作形式宾语的几个特殊结构(1)动词+it+that-从句。如：Ilikeitthatyoucame.你来了，我很高兴。Itakeit(that)hewillcomeontime.我认为他会准时来的。Youcanputitthatitwasarrangedbefore.你可以说这是以前安排的。Rumorhasitthatthedefenceministerwillsoonresign.据传闻，国防部长不久就要辞职。【说明】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。如：Idislikeitwhenyouwhistle.我不爱听你吹口哨。(from)Wereallyappreciateitwhensheofferedtohelp.她来帮忙了，我们十分感激。I’dpreferitifIdidn’thavetodosomuchwork.要是我不必做那么多工作，好就太好了。【说明】能用于此结构的动词不多，常见的有enjoy,hate,love,like,dislike,appreciate,prefer等。(3)动词+prep+it+that-从句。如：Seetoitthatyou’renotlateagain.注意千万不要再迟到。Looktoitthatthisdoesn’thappenagain.注意不要再发生这种事。Youmayrelyonitthathe’llcometomeetyou.你放心，他会来接你的。Ican’tanswerforitthathewillcome.我不能保证他会来。(from)【说明】能用于此结构的动词不多，常见的有seeto,lookto,insiston,stickto,dependon,answerfor等。(4)动词+it+介词短语+that-从句。如：IoweittoyouthatIamstillalive.多亏有你我才仍然活着。Itookitforgrantedthathewouldhelpus.我认为他会帮助我们的。【说明】能用于此结构的动词不多，常见的有takeitforgranted,bringittosb’sattention,oweittosb等。It的用法练习一．单项选择。1.WasitduringtheSecondWorldWar_____hedied?A.thatB.whileC.inwhichD.then2.Is____necessarytotakeoffourshoeswhenweenterthelab?A.everyoneB.thisC.herD.it3.Is____possibletoflytothemooninaspaceship?A.nowB.thatC.itD.man4.Idon’tthink___possibletomasteraforeignlanguagewithoutmuchmemorywork.A.thisB.thatC.itsD.it5.Sheheardofaterriblenoise,___broughtherheartintohermouth.A.itB.whichC.thisD.that6.Alicereceivedaninvitationfromherboss,____cameasasurprise.A.itB.thatC.whichD.he7.Does____matterifhecan’tfinishthejobontime?A.thisB.thatC.heD.it8.Tom’smotherkepttellinghimthatheshouldworkharder,but____didn’thelp.A.heB.whichC.sheD.it9.Theweatherturnedouttobeverygood,___wasmorethanwecouldexpect.A.whatB.whichC.thatD.it10.____isafactthatEnglishisbeingacceptedasaninternationallanguage.A.ThereB.ThisC.ThatD.It11.Ihopethereareenoughglassesforeachguesttohave_____.A.itB.thoseC.themD.one12.Itwasabout600yearsago___thefirstclockwithafaceandanhourhandwasmade.A.thatB.untilC.beforeD.when13.Ihate____whenpeopletalkwiththeirmouthsfull.A.itB.thatC.theseD.them14.ItwasonlywhenIrereadhispoemsrecently____Ibegantoappreciatetheirbeauty.A.untilB.thatC.thenD.so15.Itistheabilitytodothejob____mattersnotwhereyoucomefromorwhatyouare.A.oneB.thatC.whatD.it16.It____youthat____toblame.A.is;isB.is;areC.are;areD.are;is17.Was_____thatIsawlastnightattheconcert?A.ityouB.notyouC.youD.thatyou18.____electricityplayssuchanimportantpartinourlife?A.WhyisitthatB.WhyisitC.WhyitisthatD.Whyisthat19.Itwas____hesaid_____disappointedme.A.what;whatB.that;thatC.what;thatD.that;what20.Itwasinthelab___wastakenchargeofbyProfessorHarris___theydidtheexperiment.A.which;thatB.that;whatC.whom;thatD.which;where二.分析it成分，辨清相似句型。21.①_____iswellknowtousallthattheearthisround.②____iswellknowntousall,theearthisround.A.ThatB.AsC.ItD.Which22.①_____doesn’tmattermuchwhetherhe’llcometotheparty.②