㈠1.it作人称代词1.1.it的最基本用法是作人称代词,主要指刚提到的事物,以避免重复:Ningboisabeautifulcity,isn’tit?1.2.也可以指动物或婴儿(未知性别的婴儿或孩子):Isthisyourdog?No,itisn’t.1.3.也可指抽象事物:Itwasagreatsurprisetomewhenhedidathinglikethat.2.非人称代词itit有时并不指具体的东西,而泛指天气、时间、环境等,称为非人称的it:2.1.指天气:Itisalovelyday,isn’tit?Itisabitwindy.2.2.指时间:Itwasnearlymidnightwhenshecameback.2.3.指环境:Itwasveryquietinthecafé.2.4.指距离:Itishalfanhour’swalktothecitycentre.㈡.引导词it1.Itis+被强调部分+that...使用该句型有以下几点请注意:①强调句的谓语is或was永远用单数.ItwasyesterdaythatImetyourfatherinthestreet.②不管被强调部分是哪种状语,只能用that连接,不得使用where、when等连词.ItwasinthestreetthatImetyourfatheryesterday.③被强调部分为人时,可用who(主格或宾格)和whom(宾格)代替that,用that也行。1)Itwasyourfatherthat/whom/whoImetinthestreetyesterday.2)ItwasIthat/whometyourfatherinthestreetyesterday.④强调句中也要注意主谓一致、人称一致和否定转移的问题。Itistheywhoareourfriends.Itwasnotuntilteno'clockthatwegothomelastnight.⑤注意不要混淆强调句和其他从句。Itiswas…that…为强调句标志,去掉后仍可组成一个完整的句子,只是没被强调,而其他从句一般不具备这一特征。比较:1)Itwasteno'clockwhenwegothomelastnight.我们昨晚到家时已十点了。2)Itwasatteno'clockthatwegothomelastnight.我们昨晚是在十点到家的。要点点拔第一句不是强调句,when不可改为that,因为去掉itwas和that后,只能组成“Wegothometeno'clocklastnight.”这样一个不完整的句子;第二句是强调句,that不可改为when.2.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.=NotuntilshetookoffherdarkglassesdidIrealizeshewasafamousfilmstar.=Ididn’trealizeshewasafamousfilmstaruntilshetookoffherdarkglasses.3.it用作形式主语3.1代替主语从句1)Itis+adj.+that从句①Itisclear(obvious,true,possiblecertain....)that.....“清楚(显然,真的,肯定...)”Itisveryclearthathe’sroundandtalllikeatree.②.Itisimportant(necessary,right,strange,natural...能用于这个句型的形容词有strange、wonderful、natural、good、proper、right、wrong、well、fortunate、important、necessary、useless、likely、probable、impossible等。有时可省去should而直接用动词原形。)that...that后的从句中要用虚拟语气(should+动词原形),should可以省去,建议记住该句型中的形容词。Itisimportantthatwe(should)learnEnglishwell.2).Itis+v-ed+that从句①Itissaid(reported,learned....)that...据说(据报道,据悉...)“。ItissaidthathehascometoBeijing.②.Itissuggested(ordered/demanded/insisted/commanded...)that...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.3).Itisapity(ashame...)that...that后的从句一般用虚拟语气(should+动词原形),should可省去.表示出乎意料,常译为“竟然”。没有这种意义时,则不用虚拟语气。Itisapitythatsuchathing(should)happeninyourclass.Itisapitythatheisill.4).①Itistime(abouttime,hightime)that...该句型中that后的从句应该用虚拟语气,值得注意的是常用过去时态表示虚拟.常译为"是(正是)...的时侯..."Itistimethatchildrenwenttobed.②Itisthefirst(second...)timethat...“是第一(二)...次...”。ItisthefirsttimeIhavebeenhere.=ThisisthefirsttimeIhavebeenhere.5).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.看来...3.2.作形式主语替代不定式1).Ittakessb....todosth."做...要花费某人.."IttookthousandsofpeoplemanyyearstobuildtheGreatWall.2).Itiskind(ofsb.)todosth.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,stupid,wisewrong等。这个句型可以改写为:sb.iskindtodosth.。Itiskindofyoutosayso.=Youarekindtosayso.3).Itisnecessary(forsb.)todosth.常见的形容词有:①important,necessary,natural②easy,safe,common,normal,hard,difficult,dangerous,等。在①中的形容词作表语可以用从句改写,如:Itisimportantforhertocometotheparty.=Itisimportantthatshe(should)cometotheparty.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.It'suselesstryingtoarguewithShylock.3.3.作形式主语替代ing形式4.It作形式宾语.Wethinkitimportanttolearnaforeignlanguage.该句型中的it作形式宾语,为了记忆方便我们可称该句型为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that引导的宾语从句。Wethinkitourdutytocleanourclassroomeveryday.HefeltitimportantlearningEnglishwell.Theyfounditdifficultthattheywouldfinishtheirworkintwodays.五、特殊句型1).Itis....since...。Itis(hasbeen)5yearssincehisfatherdied.2).Itis...when...。“当...的时候,是...”Itwas5o’clockwhenhecamehere.3).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.(7)Itis/was+时间+since…从……已多久了。ItisfivemonthssinceIarrivedinNewYork.我到纽约已经五个月了。ItisfivemonthssinceIwasinNewYork.我离开纽约已经五个月了。(注意:终止性动词表示从动作发生时算起;如果是状态动词或持续性动词,则从动作或状态结束时算起。)(8)Itis+时间+before…这个句型和上面句型中时间都是时间段,如long、years、months、weeks、fivedays、threehours、twentyminutes等。不过主句的时态多用一般将来时或一般过去时。Itwillbeseveralyearsbeforewemeetagain.我们要过好几年才能再见面。Itwasnotlongbeforetheysetoutforthefront.不久他们就出发去了前线。4).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)Itseemedasifheweredying5).Itdoesn’tmatterwhether(if)...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...。Itdoesn’tmatteriftheyareold.6)makeit及时赶到;成功;办成Youcanmakeitifyouhurry.Youneedn’tworry;hewillmakeit.7)catchit被责骂;受处罚IfIcomehomelateI’llcatchitfrommymother.You’llcatchitbecauseofyourcarelessness.8).It的一些习惯用法Howisitwithyourstudy?学习好吗?That’sit.这就对了。Itwenthardwithhim.他身遇不幸。Itisallov