1、It It 的用法的用法It 的用法的用法It 最基本的用法是人称代词，主要代表刚提到的东西以避免重复。E.g:Look at that car.Its going much too fast.Eg2:Where is the car key?-I put it in your drawer.也可以代表抽象的东西。E.g:Its all my fault.也可以指动物或未知性别的婴儿。E.g:What a beautiful baby-is it a boy?Eg2:How about the baby?-Ill take care of it.还可代表一个彼此都知其何所指的东西。E.g:Wh
2、ere does it hurt?E.g2:If he doesnt come,I cant help it.Eg3:You have saved my life.I shall never forget it.非人称代词非人称代词it It 用于代替指示代词，用于代替指示代词，It 可以表示可以表示“是谁（在某处或做某事）是谁（在某处或做某事）”e.g:“Whos that?”“Its me.”E.g2:Its your mother on the phone.E.g3:“Why,its you!”she cried.It还可以用来泛指某件事。还可以用来泛指某件事。E.g:Isnt it a
3、wful!E.g2:It doesnt matter.it 有时并不指具体东西，而指天气、时间、环境、有时并不指具体东西，而指天气、时间、环境、距离等，称为非人称代词距离等，称为非人称代词it.E.g:Its raining.E.g2:Its Tuesday today.E.g3:Its quiet here.Eg4:Its two miles to the beach.替代词替代词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；替换单数可数名词或不可数名词；one只替换单数只替换单数的可数名词。的
4、可数名词。E.g:The vase on the left is more beautiful than the one on the right.The coffee produced in Brazil is more famous than that in Mexico.That只用于替换表示事物的名词，只用于替换表示事物的名词，而而one/ones替换表示替换表示人和表示事物的名词皆可。人和表示事物的名词皆可。E.g:His younger sister is taller than the elder one.I need the plastic bags,not the paper
5、 ones.The computers in our school are connected to the Internet while those in their school arent.The football players on our team seem to be more energetic than those on your team.That/those用于替换有定冠词的名词；用于替换有定冠词的名词；one/ones用于用于替换有不定冠词的名词。替换有不定冠词的名词。E.g:The style of the building is similar to that of
6、 a temple.A CD player made in Japan costs more than one made in Hong Kong.That/those一般不带前置定语，但必须有后置定语。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都可。当替换词的后置定语用所有格的of短语或当替短语或当替换词被所有格修饰时，不用换词被所有格修饰时，不用one/ones而用而用that of/those of.E.g:I like the vase better than the one/that in another shop.The windows
7、of your flat are cleaner than those of mine.A grandparents job is easier than that of a parent.2)it,this 和和 that都可以替代前文已提到的事或情况，细微差别在于都可以替代前文已提到的事或情况，细微差别在于it不不如其余两者那么强调。如其余两者那么强调。E.g:So she decided to paint the door pink.It upset the neighbours a bit.So she decided to paint the house pink.That real
8、ly upset the neighbours,as you can imagine.当前面提到的事物不止一件时，当前面提到的事物不止一件时，it通常指最先提到的通常指最先提到的事物，而事物，而This/that是指最后提到的事物。是指最后提到的事物。E.g:We keep the ice cream machine in the spare room.It is mainly used by the children.(指指 the machine)We keep the ice cream machine in the spare room.This/That is mainly used
9、 by the children.(指指the spare room)This可以出现在它所指代的事物之前；而可以出现在它所指代的事物之前；而that则指上文则指上文所提到的事物。所提到的事物。E.g:Listen to this!We will have three days off.“A penny saved is a penny earned.”Who said that?3)It和和oneIt用以指特定的前面提到过的事物，即：用以指特定的前面提到过的事物，即：it和它替换的和它替换的是同一个事物，是同一个事物，it前无修饰语；而前无修饰语；而one用于替换与前提用于替换与前提事物有共
10、同之处但并不完全一样的事物，因此，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。之前或之后一定有修饰语来加以区别。E.g:I bought a dictionary three years ago and I am still using it now.I bought a dictionary three years ago but I am going to buy a new one soon.形式主语形式主语it有下面几种类型：有下面几种类型：Be+形容词形容词+不定式不定式 e.g:Its better to be early.Be+名词名词+不定
11、式不定式 e.g:It was his duty to take care of the orphans.Be+介词短语介词短语+不定式不定式 e.g:Its beyond me to say why.It+及物动词及物动词+宾语宾语+不定式不定式 e.g:It makes me sick to think about it.Be+名词名词+动名词动名词 e.g:Its no good standing here in the cold.Be+形容词形容词+动名词动名词 eg:Its helpless trying to convince her.其他结构其他结构+动名词动名词 e.g:It
12、doesnt matter waiting a few more days.用于由用于由that 引导的主语从句，有下面几种类型：引导的主语从句，有下面几种类型：it+be+形容词形容词+that从句从句：e.g:It is natural that they should have different views.it+be+名词名词+that从句从句:e.g:Its a shame that youre sick.it+动词（动词（+宾语）宾语）+that从句从句 e.g:It happened that she wasnt in that day.Eg2:It never occurre
13、d to me that perhaps she was lying.It+动词的被动语态动词的被动语态(said/believed/thought/expected/reported/known+that从句从句 e.g:Its said that there has been an earthquake in India.形式宾语形式宾语it:it 可以代表不定式可以代表不定式：e.g:She found it difficult to convince him.Eg2:He felt it his duty to take care of them.It 代表代表that引导的从句引导的
14、从句：e.g:I took it for granted(that)you would be coming.It间或代表连接代（副）词引导的从句：间或代表连接代（副）词引导的从句：E.g:He hasnt made it clear when he is coming back.Eg2:They havent made it known where the meeting is to take place.用用it起始的句型归纳：起始的句型归纳：1）it+be+形容词形容词+从句：从句：e.g:It is not clear to me why he behaved like that.2）i
15、t+be+名词名词+从句从句:e.g:Its a puzzle how life began.3）it+动词（动词（+宾语）宾语）+从句从句 e.g:It doesnt matter much where we live.eg2:It makes no difference whether we go by train or by boat.4）it+动词的被动语态动词的被动语态+从句从句e.g:It is not decided who will edit it.5）it+动词动词be+that从句从句 e.g:No,it couldnt be that they were interest
16、ed in him.6）It+be+一点时间一点时间+whenE.g:It was Christmas Eve when I got the news of his being killed in a car crash.7）It+be+一段时间一段时间+sinceE.g:It is/has been three week since I last heard from him.8）It is time to do/that(谓语用过去时态）谓语用过去时态）E.g:It is time for us to give the house a thorough cleaning.It is tim
17、e that we gave the house a thorough cleaning.9）It+be+the first/second time that(谓语动词用完成时态）谓语动词用完成时态）E.g:It is the first time in history that two Nobel Prizes have been awarded to the same person.10）It takes sb.Time to doE.g:It took Mary 20 minutes to choose a suitable dress for the party.There起始的句型归
18、纳：起始的句型归纳：1）there live/stand/lie/existE.g:There stands a big tree at the entrance to the temple.There lay a ditch two metres wide ahead.2)There come/go/appear/occur/follow用于描述某事的用于描述某事的发生或某个动作的开始。发生或某个动作的开始。E.g:There will follow a break of 10 minutes and then we will go on with the lecture.3)There b
19、eing（独立主格结构）（独立主格结构）E.g:There being nothing left in the fridge,we had to do some shopping first.4)there to be结构常见于动词结构常见于动词intend,mean,consider,hate,want等词后。等词后。E.g:No one would expect there to be a war in his country.I dont want there to be another accident like this.5)There is no need to doE.g:The
20、re is no need to wait for the bus since we can take you in our car.若名词是若名词是use,good,harm,sense,point时时There is no+名词名词+in doingE.g:There is no point in arguing with him.He wont listen to anyone.6)There appear/seem/is likely/is certain to beE.g:There seems to be something wrong with the electric fan.
21、There is likely to be more people at the speech contest than expected.It 用于强调句用于强调句结构：结构：It+动词动词be+强调部分强调部分+who(whom)/that+其其他部分他部分it可以用来对句子的某一成分加以强调。可以用来对句子的某一成分加以强调。Eg:Nancy saw your sister in Tokyo last week.It was Nancy who saw your sister in Tokyo last week.It was your sister whom Nancy saw in
22、Tokyo last week.It was in Tokyo that Nancy saw your sister last week.It was last week that Nancy saw your sister in Tokyo.有些否定句也可以改成这种强调结构：有些否定句也可以改成这种强调结构：I didnt hear from her until last summer.It wasnt until last summer that I heard from her.I didnt do all this for myself.It wasnt for myself that
23、 I did all this.问句也可变成这种结构：问句也可变成这种结构：Who called him“comrade”?Who was it that called him“comrade”?How did you forget to lock the door?How was it that you forgot to lock the door?Ex:把下列句子改为强调句：把下列句子改为强调句：1.Tom broke the window last night.2.They want money.3.Peter saw his friend in the park yesterday.4.I didnt have an opportunity of seeing her again for several years.5.Why does everyone think Im narrow-minded?6.I didnt receive my letter until yesterday?7.Did Dick call the meeting last week?8.Did it happen in 1980?
