it作形式主语课件.ppt

,以形式主语it引导的句型,为避免主语冗长,句子头重脚轻,经常用it作形式主语,主语从句放在后面作真正的主语。,1.Itiscertainthathewillsucceed.2.Itisnotknownwhetherhewillgothere.3.Ithasnotbeendecidedyetwhentheyllstarttheproject.,“It”isusedasemptysubject.,形式主语,1.Itis名词从句Itisafactthat事实是Itisanhonorthat非常荣幸Itiscommonknowledgethat是常识能获邀参加你们的婚礼真是不胜荣幸风就是流动的空气,这是常识可惜他由于一个拼写错误没有得满分,ItsagreathonorthatIhavebeeninvitedtoyourwedding.,Itscommonknowledgethatwindismoving/flowingair.,Itsapitythathedidntgetfullmarksbecauseofaspellingmistake.,句型1.,2.Itis+adj.+从句Itscertainthat肯定Itispossiblethat.很可能Itisunlikelythat.不可能Itisobviousthat很明显Itisnecessaryimportantnatural.that*_(很可能)shewillcomebacktomorrow.*_(很明显)thismeasureiseffective.,+(should)+do,Itispossiblethat,Itisobviousthat,句型2.,另注意在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时，谓语动词要用虚拟语气“(should)+do”，常用的句型有：Itisnecessary(important,natural,strange,etc.)thatItissuggested(requested,proposed,desired,etc.)that,3.Ithappens(seems,looks,appears)that.该句型中it是形式主语，that引导的是主语从句,主句中的happen,seem等词是不及物动词,Ithappened(sohappened)thathemethisteacherinthestreet.碰巧Itseemsthathewillbebackinafewdays.,句型3.,Itseemsthatsb.do/bedoing/havedone/haddone=Sb.seemstodo/bedoing/havedone/tobedone/tohavebeen,ItseemedthathehadbeentoBeijingbefore.=HeseemedtohavebeentoBeijingbefore.,It+不及物动词+从句Ithappenedthat.碰巧Itoccurredtomethat我突然想起*_(刚好)Icameintotheofficeatthattime.*_(我突然想起)Iforgettosenttheletter.,Ithappenedthat,Itoccurredtomethat,句型4.,据说他读过这篇小说,.,Itwassaidthathehadreadthisnovel.=Hewassaidtohavereadthisnovel.,It+be+-ed分词+that-从句Itissaidthat据说Itisknownthat据了解Itisreportedthat据报道Itisbelievedthat据认为,据说她两年前在美国留学ItssaidthathestudiedinAmericatwoyearsago2.据说她现在正在美国留学ItssaidthatheisnowstudyinginAmerica3.据说她现在懂三国外语Itssaidthatheknowsthreeforeignlanguages,HeissaidtohavestudiedinAmericatwoyearsago.HeissaidtobestudyinginAmericanow.Heissaidtoknowthreeforeignlanguages.,Itissuggested(ordered,required.)that.该句型和上一个同属一个句型。主句中的过去分词是表示请求，建议，命令等词时，that后的从句要用虚拟语气（should+动词原形），should可以省。常译为“据建议；有命令）”。,Itissuggestedthatthemeeting(should)beputoff.Itwasorderedthatwe(should)arrivethereintwohours.,注意,Itisdoubtfulwhethershewillbeabletocome她是否能来还不还说。Itwasclearenoughwhatshemeant.她的意思还不太清楚。Itwontmaketoomuchdifferencewhetherhewilljoinus.他是否参加我们队不会太重要。Hasitbeenfoundoutwhosettherecord?是谁破了纪录弄清楚了吗？,5、可用whether和疑问词引导从句的有：Itisdoubtful(notknown,notdecided,notmadeclear,tobefoundout,beingconsidered,amystery,aquestion,+that/whether,句型5,Itisstillaquestionwhenweshallhaveoursportsmeeting.Itisamysterytomehowitallhappened.这事是怎么发生的还是个谜。Ithasntmadeclearwhenthenewroadistobeopenedtotraffic.新路什么时候通车还不清楚。,6.Itdoesntmatterhow/whether(if)结构中的主语从句不可提前。该句型中whether(if)引导的从句是真正主语，该句型常译为“不论（是否）没关系。,Itdoesntmatteriftheyareold.Itdoesntmatterwhowillgoinsteadofme.谁代替我去不重要。,句型6,Itdoesntmatterwhetherheiswrongornot.(right)Whetherheiswrongornotdoesntmatter.(wrong),该句型是强调句型。被强调部分可以是主语，宾语，表语或状语。强调的主语如果是人，that可以由who换用。,Itwasabout600yearsagothatthefirstclockwasmade.Itwastheythat(who)cleanedtheclassroomyesterday.ItwasinthestreetthatImetherfather.,7.Itis+被强调部分+that.,1.正确选用is或was.2.强调部分是人，可以用who.3.强调主语，that或who后面的谓语形式与主语一致不能强调谓语,注意,8.Itisnotuntil+被强调部分+that.该句型也是强调句型。主要用于强凋时间状语，译成汉语“直到才”，可以说是not.until.的强调形式。,=ItwasnotuntilshetookoffherdarkglassesthatIrealizedshewasafamousfilmstar.,Ididntrealizeshewasafamousfilmstaruntilshetookoffherdarkglasses.,=NotuntilshetookoffherdarkglassesdidIrealizeshewasafamousfilmstar.,9.Itisthefirst(second)timethat该句型要和上一个句型区别开来。该句型中的that从句不用虚拟语气，而用完成时态。至于用什么完成时态，由主句的谓语动词的时态决定。如果是一般现在时，后面从句用现在完成时态；如果是一般过去时，后面从句则用过去完成时态。该结构中that可以省去；it有时用this替换，常译为“是第一（二）次”。,It(This)isthefirsttimeIhavebeenhere.,It(This)wasthefirsttimeIhadbeenhere.,10.Itissince.该句型主要用作处理瞬间动词的完成时，又要和表示一段时间的时间状语连用的问题。主句中是时间作表语，其时态是现在时或完成时，since引导的从句通常是一般过去时态，而且是瞬间动词。如果主句是一般过去时，从句则用过去完成时。,Itis(hasbeen)5yearssincehisfatherdied.,Itwas1949whenIwasborn.,Itwasin1949thatIwasborn.,区别句下面这个句子：,11.Itis.when.该句型中的when引导的是一个时间状语从句，主句中的it指时间，表语由具体的时间充当。常译为“当的时候，是”。,Itwas5oclockwhenhecamehere.,强调句型,时间状语从句,12.Itbe.before.该句型主句中的it指时间,主句中的时态常是一般将来时或过去时两种时态主句中的表语多是long,notlong,3days,2weeks等表示时间段的词或短语。常译为“之后”。,Itwas3daysbeforehewenttoBeijing.Itwillbenotlongbeforehefinisheshisjob.,要过好几个月她才会适应这项工作,Itwillbemonthsbeforesheisfitforthejob.,过了一星期他回来了,Itwasaweekbeforehecameback.,过了不久，她认识到她错了,Itwasnotlongbeforesherealizedshewaswrong.,他离开中国已经10年了,Itis10yearssinceheleftChina.,如以过去某一时间为基点，则为：Itwas10yearssinceHehadleftChina.,区别句意：,ItisthreeyearssinceIlivedhere.ItisthreeyearssinceIhavelivedhere.ItisthreeyearssinceIbegantolivehere.,我不住在这里已经有三年了。,后两句的含义是：我住在这里已经有三年了。,Itis+段时间+since./Ithasbeen+段时间+since.表示“从起已有多长时间了”。,Itisthreeyearssincehesmoked.他不吸烟已有3年了。试比较：Itisthreeyearssincehebegantosmoke.Itisthreeyearssincehehassmoked.两句均意为：他吸烟已有3年了。,用法：since从句中常用一般过去时，(1)若从句中是持续性动词的一般过去时，则表示该动作结束有多长时间了则翻译为“已经不再多长时间了”；，(2)若是短暂性动词，的一般过去时，则表示该动作发生后，距离现在有多长时间了则翻译为“已经.多长时间了”(3)若是持续性动词的现在完成时，则表示动作和状态延续到现在(说话时刻)，其表示的时间的起点应从动作发生之时算起。,注意：在这种结构中，since引导的从句绝对不能用否定式的谓语动词来表示否定意义。,他好久没学汉语了。误：ItisalongtimesincehedidntstudyChinese.正：ItsalongtimesincehestudiedChinese.(studied为持续性动词，应从其动作结束时算起),ItisthreeyearssinceIwasacollegestudent.,我已经毕业三年了。,ItisthreeyearssinceIbecame/havebeenacollegestudent.,我成为一名大学生已经两年了,13.Ittakessb.todosth.该句型中的不定式是真正的主语，it是形式主语，句型中的直接宾语是时间。常译为“做要花费某人”。,IttookthousandsofpeoplemanyyearstobuildtheGreatWall.,14.Itisnogood(use)doingsth.该句型中的真正主语是动名词短语，主句中的表语可以是nogood,(notanygood),nouse,(notanyuse)。,ItisnogoodlearningEnglishwithoutspeakingEnglish.,ItisnouseforhimtolearnEnglishwithoutspeakingit.,15.Itlooks(seems)asif.该句型中it无意义。asif引导一个状语从句。常译为，“看起来好象如果与事实不相符合，则用虚拟语气,Itlooksasifheisill.（真的病了）Itlooksasifhewereill.（没有生病）Itseemedasifheweredying.,16.Itiskind(ofsb.)todosth.该句型中的不定式短语是真正主语，如果不定式的逻辑主语是由of引起，主句中的形容词必须是能表示逻辑主语特征的形容词。常见的有:bad,brave,careless,clever,cruel,foolish,good(好心的),honest,horrible,kind,lazy,modest,naughty,nice(有教养的),polite,rude,silly,stupid,wise,wrong(错误的)等。这个句型可以改写为：sb.iskindtodosth.,Itiskindofyoutosayso.=Youarekindtosayso.,17.Itisnecessary(forsb.)todosth.该句型与上一个同属一个句型。如果不定式的逻辑主语是由for引起，主句中的形容词通常是表示重要性，紧迫性,频繁程度,难易,安全等情况的形容词。常见的形容词有：,important,necessary,naturaleasy,safe,common,normal,hard,difficult,dangerous,unusual,rare,impossible,pleasant等。,在中的形容词作表语可以用从句改写，如：,Itisimportantforhertocometotheparty.=Itisimportantthatshe(should)cometotheparty,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：ItissaidthatPresidentJiangwillvisitourschoolnextweek.ThatPresidentJiangwillvisitourschoolnextweekissaid.（3）Ithappens/occurs结构中的主语从句不可提前。例如：Itoccurredtohimthathefailedintheexamination.Thathefailedintheexaminationoccurredtohim.,(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)Isthatitwillrainintheeveninglikely?(wrong),（4）Itdoesntmatterhow/whether结构中的主语从句不可提前。例如：Itdoesntmatterwhetherheiswrongornot.Whetherheiswrongornotdoesntmatter.,1.Itnowappears_theyareinneedofhelp.A.thatB.whichC.whatD.how2.Itisgoodnews_theywillarriveinafewdays.A.whichB.whatC.thatD.how3.It_Joedrivesbadly.A.thoughtthatB.thinksthatC.isthoughtD.isthoughtthat,4.Ihavealwaysbeenhonestandstraightforward,anditdoesntmatter_thatImtalkingto.A.whoisitB.whoitisC.itiswhoD.itiswhom,5.Itisprettywellunderstood_controlstheflowofcarbondioxideinandouttheatmospheretoday.A.thatB.whenC.whatD.how,选C，从句缺少主语，what正好可以作为主语，意思大家知道是什么控制着二氧化碳进出大气层。,6.Itisimportantthat_oureducationinallavailableways.A.wemustdevelopB.weshalldevelopC.wewoulddevelopD.weshoulddevelop7.Itisnecessarythat_bytheendoftheweek.A.wegoteverythingreadyB.wehavegoteverythingreadyC.WegeteverythingreadyD.wemustgeteverythingready8.Itwasnaturalthat_.A.mypictureswouldsurprisethemB.mypicturessurprisedthemC.mypicturesshouldsurprisethemD.mypictureswouldhavesurprisedthem9.Iwonder_.A.whetherornotIllcatchthelastbusB.ifornotIllcatchthelastbusC.thatIllcatchthelastbusornotD.thatIllcatchthelastbus,10._madetheschoolproudwas_morethan90ofthestudentshadbeenadmittedtokeyuniversities.A.What;becauseB.What;thatC.That;whatD.That;because,意思：令这所学校骄傲的是90的学生都被重点大学录取了,B是个主语从句和表语从句,11._wewillgocampingtomorrowdependsontheweather.A.IfB.WhetherC.ThatD.Where12._thattheycanpassthewrittenexamthistime.A.ThatishopedB.ItishopedC.IthopesD.Thathopes,13._leavestheroomlastoughttoturnoffthelights.A.AnyoneB.ThepersonC.WhoeverD.Who,14._isafactthatEnglishisbeingacceptedasaninternationallanguage.A.ThereB.ThisC.ThatD.It,C,D,15._inthenewspaperthatthepriceoffoodwillgoup.A.ItsaysB.ItissaidC.IthassaidD.Heissaid,16.Itworriedherabit_herhairwasturninggrey.A.whileB.thatC.ifD.for,B,B,17.TheForeignMinistersaid,“_ourhopethatthetwosideswillworktowardspeace.”A.ThisisB.ThereisC.ThatisD.Itis,D,18.Itisnecessarythatacollegestudent_atleastaforeignlanguage.A.mastersB.shouldmasterC.masteredD.willmaster,B,19._hisdreamofgoingtocollegewillcometrueisuncertain.ThatB.WhetherC.IfD.Evenif20.Itisknowntous_wherethereispollution,thereisharm.A.whichB.whereC.whatD.that,21.-Isawyourneighborbreakyourwindowwithabasketball.-_itmademenearlymad.A.ThathebrokeB.WhathebrokeC.Hebr