it做形式主语或宾语的用法

Theuseof“it”(I)HefounditdifficulttostopsmokingIthinkitbestthatyoushoulddomoreexercise.ShethoughtitnogoodworryingabouthimIt作形式宾语代替不定式、动词-ing短语、或从句。1.It用作形式宾语当不定式（短语）、动名词（短语）或从句在句子中作宾语时，为保持平衡，避免句式结构的混乱，常用it作形式宾语，而将真正的宾语放在句尾。此时it只起引导作用，无意义。S+v+it+adj.n(forsb)todosth..从句doingsth+完成句子（1）They________________（发觉……难）tofinishtheirworkintwodays.（2）We________________（认为……是我们的职责）tocleanourclassroomeveryday.（3）Itisimportant_______（对她来说）tocometotheparty.founditdifficultthinkitourdutyforher作形式宾语(PreparatorySubject)为了记忆方便我们把该句型总结为6123结构。6指主句中常用的动词：think,believe,make,find,consider,feel；1指的是形式宾语it；2指的是宾补的两种形式：形容词或名词；3指的是真正宾语的三种形式：不定式短语，动名词短语或从句。Wethinkitourdutytocleanourclassroomeveryday.HefeltitimportantlearningEnglishwell.Theyfounditdifficultthattheywouldfinishtheirworkintwodays.1.Thefactthatshewasforeignmade____difficultforhertogetajobinthatcountry.(2010.辽宁）A.SoB.muchC.thatD.it2.Thedoctorthought____wouldbegoodfortohaveaholiday.（2010.全国II)A.thisB.thatC.oneD.It3.Idon’tthink_______possibletomasteraforeignlanguagewithoutmuchmemorywork..(MET90)A.thisB.thatC.itsD.it4.It作形式宾语的特殊用法1.某些表示“喜、怒、哀、乐”的动词，如like,enjoy,love,hate,dislike,appreciate等后往往不能直接接宾语从句；必须先由it担任形式宾语,再接从句.Wewouldmuchappreciateitifyoucoulddousthatfavour.要是你们能帮我们这个忙，我们将非常感激。I'dpreferitifIdidn'thavetofinishthework.要是我不必完成那项工作，那就太好了。2.某些含有介词的动词短语如seeto,dependon,answerfor,relyon,insiston,lookto,stickto等结构中往往不能直接接宾语从句；必须先由it担任形式宾语,再接从句.I'llseetoitthateverythingisreadyintime.我将负责按时做好一切准备。YoumaydependonitthatTomwillhelpyouwithyourEnglish.(你放心，汤姆会帮助你学英语的。)I’mcountingonitthatyouwillcome.我指望着你会来。1.Ilike_______intheautumnwhentheweatherisclearandbright.(MET2004)A.thisB.thatC.itD.one2.Ihate__whenpeopletalkwiththeirmouthsfull.(MET98)A.itB.thatC.theseD.themItisamazingthatatmyageIamstillfit.Itiseasytobecomeaddictedtosmoking.itisnogoodcryingoverspiltmilk.(覆水难收)It作形式主语代替不定式、动词-ing短语、或从句。2.It用作形式主语当不定式（短语）、动名词（短语）或从句在某个句子中作主语时，为保持句子结构前后平衡，避免头重脚轻，因此常用it作形式主语置于句首，而将真正的主语放在句尾。此时it只起先行引导作用，本身无词义。Itbe+adjnp.p(for/ofsb)todosth主语从句doingsth+1.It+be+adj.+主语从句这是主语从句最常见的一种结构。ItisuncertainwhetherhecancometoJenny’sbirthdaypartyornot.注意：如若形容词为important/necessary，good/wrongnatural...表达一种要求，命令或者责备时，多使用虚拟语气（should+V).但是如果只是表示陈述一个事实而不是强烈的感情，完全可以用一般的陈述语气。不过考试建议你还是多用虚拟语气Itisimportantthatwe(should)learnEnglishwell.Itisnecessarythathe(should)rememberthesewords.2.It+be+过去分词+主语从句，这类过去分词有：announced,believed,expected,hoped,decided,reported,said,shown等，如：Itisreportedthat16peoplewerekilledintheearthquake.Itisnotdecidedwhowillgivetheoperationtothepatient.ItissaidthathehascometoBeijing.注意：如果主句中的过去分词是表示请求，建议，命令等词如：suggested/ordered/demanded/insisted/commanded...等时that后的从句要用虚拟语（should+动词原形），should可以省；常译为，“据建议；有命令．．．）Itissuggestedthatthemeeting(should)beputoff.Itwasorderedthatwe(should)arrivethereintwohours.3.It+be+名词词组+主语从句这类名词有：afact,apity,ashame,anhonour，aquestion等，如：It’sapitythatyoumissedtheexcitingfootballmatch.Itremainsaquestionwhetherhewillcomeornot.注意：如若表示出乎意料之意时,从句一般用虚拟语气常译为“竟然”。没有这种意义时，则不用虚拟语气。Itisapitythatsuchathing(should)happeninyourclass.4.It+不及物动词+主语从句这类不及物动词有：appear,seemhappen，matter等。译为好像……/碰巧……/如：Itseemedthathedidn’ttellthetruth.IthappenedthatIwasoutwhenhecalled.5.It+be+形容词+（forsb.）+动词不定式这类句型常用形容词easy,difficult,hard,important,possible，wise等作表语，有时候为了强调不定式动作的执行者，常在不定式前加forsb，译为“对某人来说做某事怎么样”如：It’snecessaryfortheyoungtomastertwoforeignlanguage.Itisunwisetogivethechildrenwhatevertheywant.6.It+be+形容词+ofsb.+动词不定式这类形容词常是表示心理品质,性格特征的形容词，如：kind,nicestupid,clever,foolish,polite,impolite,silly,selfish,considerate等。某人和这些形容词可以构成主系表结构。如：It’sverykindofyoutohelpmewiththework.=Youarekindtohelpme.Itseemedselfishofhimnottosharehisdictionarywithothers.=Heseemedselfishnottosharehisdictionarywithothers.7.It+be+名词词组+动词不定式，如：Itisnotagoodhabittostayuptoolate.8.It+be+名词或形容词+动名词，这类名词和形容词常常是：good,nogood,nouse,awasteof…,useless,senseless等，如：It’sawasteoftimetalkingtoheranymore.Itisnousearguingaboutthematterwithhim.9.It+take(sb.)+时间（金钱）+动词不定式，译为，做某事花了某人多长时间或多少钱。如：Ittooktheworkersalmostthreeyearstofinishbuildingthedam.Itwilltakeawholedaytogettothetopofthemountainonfoot.实战练习高考真题1.Infactisahardjobforthepolicetokeeporderinanimportantfootballmatch.(2001上海)A.thisB.thatC.thereD.it2.isafactthatEnglishisbeingacceptedasaninternationallanguage.(NMET1995)A.ThereB.ThisC.ThatD.It3.Isnecessarytotakeoffourshoeswhenweenterthelab?(MET88)A.everyoneB.thisC.herD.it4._____willtakeyoualotoftimetofindhiminthecrowd.A.ItB.IC.WeD.They5.Itisnousehis_________there,thesituationishopelessnow.A.togoB.tobegoingC.goingD.havinggone•6.Is_______necessarytocompletethedesignbeforeNationalDay?(MET89)A.thisB.thatC.itD.he•7.Does_______matterifhecan’tfinishthejobontime?(MET91)A.thisB.thatC.heD.it8、(2006,全国Ⅱ)Itisno__arguingwithBillbecausehewillneverchangehismind.A.useB.helpC.timeD.way9.(2004,北京)TheForeignMinistersaid,“__ourhopethatthetwosideswillworktowardspeace.A、ThisisB、ThereisC、ThatisD、ItisTheUsageof“it”常见用法特殊用法6123三大句型形式主语形式宾语Summary九个句型Itbe+adj…Itbe+n…Itbe+p.p…Homework世纪金榜unit3语法专练选择1-10