1.替代词one,ones,that,those,it,this,that1)one,ones,that,thoseThat替换单数可数名词或不可数名词;one只替换单数的可数名词。Eg:Thevaseontheleftismorebeautifulthan__________ontheright.ThecoffeeproducedinBrazilismorefamousthan__________inMexico.theonethatThat只用于替换表示事物的名词,而one/ones替换表示人和表示事物的名词皆可。Eg:Hisyoungersisteristallerthantheelder___.Ineedtheplasticbags,notthepaper______.oneonesThat/those一般不带前置定语,但必须有后置定语。One/ones都可。当替换词的后置定语用所有格的of短语或当替换词被所有格修饰时,不用one/ones而用thatof/thoseof.Eg:Ilikethevasebetterthan________________inanothershop.Thewindowsofyourflatarecleanerthan_________ofmine.Agrandparent’sjobiseasierthan________ofaparent.ThecomputersinourschoolareconnectedtotheInternetwhile__________intheirschoolaren’t.theone/thatthosethatthoseThat/those用于替换有定冠词的名词;one/ones用于替换有不定冠词的名词。Eg:Thestyleofthebuildingissimilarto_________ofatemple.ACDplayermadeinJapancostsmorethan________madeinChina.thatoneEg:IboughtadictionarythreeyearsagoandIamstillusing______now.IboughtadictionarythreeyearsagobutIamgoingtobuyanew_______soon.It用以指特定的前面提到过的事物,即:it和它替换的是同一个事物,it前无修饰语;而one用于替换与前提事物有共同之处但并不完全一样的事物,因此,one之前或之后一定有修饰语来加以区别。2.It和oneitoneIt引起的几个易混淆的时间句型It+be+时间+since-clause这个句型表示从since从句谓语动作发生以后到现在或过去所经过的一段时间,意为“自从......以来已多久了”Itisthreeyearssincehisfatherpassedaway.It+be+时间+before-clause这个句型中的时间一般为表示一段时间的词语(如:alongtime,months,weeks,days,hours,minutes),主句中的谓语动词用肯定式,意为“过多长时间才......”。主句的谓语动词是否定式时,意为“没过多长时间就......”。主句的时态可用过去时was或将来时willbe;用was时,before从句的动词用一般过去时;用willbe时,before从句常用一般现在时。她没过多久就背会了那些诗歌。Itwas_______________shelearnedthosepoemsbyheart.过了很久警察才来。Itwas______________thepolicearrived.要过好几个小时他才会作出决定。It__________hoursbeforehemakesadecision.要不了几个小时我们还会再见面的。__________________beforemeetagain.notlongbeforelongbeforewillbeItwillnotbehours3.It+be+时间+when-clause这个句型中,it指时间,而且表示时间的词语前没有介词(时间一般为具体时间)。主句中的谓语动词和从句中的谓语动词在时态上一般是一致的,主句是willbe,when从句用一般现在时代替将来时。Itwasalready8o‘clockwhenwegothome.Itwasthenextmorningwhenwefinishedourwork.Itwillbemidnightwhentheygetthere.It+be+时间+that-clause这个句型是个强调句型。例如:Itwastwoyearsagothathemadeanimportantinvention.(原句是:__________________________________)Itwasat5o’clockthathepractisedplayingtheviolininthemorning.(原句是:________________________________)比较:Itwas5o’clockwhenhestartedinthemorning.(5o‘clock前没有介词,这是个定语从句)Hemadeanimportantinventiontwoyearsago.Hepractisedplayingtheviolinat5o‘clockinthemorning.•It+be+time+that-clause这个句型属虚拟语气结构,不管主句中用的是is或was,that从句都须用动词的过去式或should+动词原型(但不及用过去式普通),在time之前有时可加上high或about以加强语气。例如:Itistime(that)wehandedinourexercises.(=Itistimethatweshouldhandinourexercises.)Itishightime(that)shewrotealettertoherboyfriend.•It/This/That+thefirst(second,third…)time+that-clause这个句型表示截止到说话时为止的某人的一种经历,关键是注意time前有序数词,主句是is时,从句要用现在完成时;如果主句用一般过去时was,则从句须相应地用过去完成时。例如:Thisisthefirsttime(that)theseEuropeans____________theGreatWall.Itwasthefifthtime(that)I___________afriendlyvisittoAfrica.hadpaidhavevisited结构:It+动词be+强调部分+who(whom)/that+其他部分it可以用来对句子的某一成分加以强调。It用于强调句Eg:NancysawyoursisterinTokyolastweek.ItwasNancywhosawyoursisterinTokyolastweek.ItwasyoursisterwhomNancysawinTokyolastweek.ItwasinTokyothatNancysawyoursisterlastweek.ItwaslastweekthatNancysawyoursisterinTokyo.有些否定句也可以改成这种强调结构:Itwasn’tuntillastsummerthatIheardfromher.Ididn’tdoallthisformyself.Itwasn’tformyselfthatIdidallthis.问句也可变成这种结构:Whocalledhim“comrade”?Whowasitthatcalledhim“comrade”?Howdidyouforgettolockthedoor?Howwasitthatyouforgottolockthedoor?1.Tom‘smotherkepttellinghimthatheshouldworkharder,but___didn’thelp.A.heB.whichC.sheD.it1.As___happens,Ihavebroughtmyumbrellawithme.A.itB.thisC.thatD.such3.___hasalreadybeenpointedout,grammarisnotasetofdeadrules.A.AsB.ItC.ThatD.This4.Itwassevenforty-five___hefinishedthework.A.whenB.thatC.whenD.beforeDAAA5.Wasitbecauseitsnowedlastnight___hedidn‘tcome?A.whyB.thatC.whenD.which6.Does___matterifhecan’tfinishthejobontime?A.thisB.thatC.heD.it7.Europeanfootballisplayedin80countries,making___themostpopularsportintheworld.A.whichB.thisC.thatD.it8.___isnodoubtthathewillsucceedinhisexperiment.A.ItB.ThisC.ThatD.ThereBDDD9.Itworriedabit___herhairwasturninggray.A.whileB.thatC.ifD.for10.Itwasnot___shetookoffherdarkglassesIrealizedshewasafamousfilmstar.A.when;thatB.until;thatC.until;whenD.when;thenBB