知识要点：
一、代词it
代替前文提到过的东西或事情，用作人称代词。 This is a new dictionary. I bought it yesterday.
这是一本新词典，我昨天买的。
Tom joined the army last mouth. Do you know about it?
汤姆上月入伍了，你知道这事吗？
代替指示代词，起着this或that的作用 Is this your car? No, it isn’t. 这是你的汽车吗？不是。
What’s that?—It’s a video. 那是什么？它是一台录像机。
Whose room is this?—It is theirs.这是谁的房间，是他们的。
指明某人或某物的身分，还可指不明性别的婴儿 Who’s there? It’s me. (It’s John) 谁在那儿？是我。（是约翰）
Go and see who it is that rings. It’s Bill.
去看看是谁来的电话，是比尔。
The Greens have a new baby. It’s lovely.
格林家有一个新生婴儿。它很可爱。
指时间，距离，自然现象（天气，气候，明暗）量度，价值等 It’s Sunday today.  今天是星期天。
It’s three months since he came here.
自从他来到这里，已经三个月了。
How far is it to the Great Wall .到长城有多远？
It’s getting dark.  天快黑了。
—How much is the coat?  —It’s ninety dollars.
这件衣服多少钱？九十美元。

二、引导词it
代替不定式短语 
It is up to you to decide.  这事要由你决定。
It makes me happy to hear you have recovered.
听说你恢复了健康，这使我很高兴。

代替动名词短语
 It’s no good smoking.   吸烟没有好处。
It’s worthwhile working the whole night on the problem.
用整夜的时间来研究那个问题是值得的。

代替主语从句 
It doesn’t matter what you do. 你干什么都没有关系。
It seems that everyone has known the news.
好象大家都知道这个消息。

代替不定式短语 
I consider it better to be early.
我认为能够早一些更好。
We found it impossible to get there before July .
我们觉得，要在七月以前到达那里是不可能的。

代替动名词短语 
We thought it no use doing that.
我们认为做那事没有用。

代替宾语从句 
The teacher makes it clear that everyone should hand in his homework on time .
老师清楚地指出，每个人都应该按时交作业。

三、it在强调结构中
强调句型：It is (was) +被强调部分+ that (who) + 其它
主 语 
It is I who am to blame. 是我该受责怪。
It was your uncle that (who) came yesterday.
昨天来的是你叔叔。 原句的谓语动词如果是现在或将来时态用It is …that(who)如果原句谓语动词是过去时态，则用It was…that(who)。在
宾 语 
It was a new pen that Mother gave me .
母亲给我的是一支新钢笔。 强调时间，地点，原因或方式时不要用when, where, how, 必须用that。
 地点 It was in the classroom that I left my umbrella.
我把雨伞就落在了教室里。 
时间 
It is at eleven that the train leaves.
火车是在十一点钟离开。 
 方式 
It was just as he ordered that I acted.
我正是照他吩咐的那样做的。 
原因 
It was because he was in trouble that I tried my best to help him.
正是因为他处境困难我才尽力帮助他。 
宾 补 
It was red that we painted the gate.
我们把门油漆成红的颜色。
It was chairman that they elected him .
他们选他担任的是主席的职务。
 
there be结构

肯定句     there be +主+其它 
There is a map on the wall. 墙上有张地图。

否定句    
there be + not +主+  There is not a map on the wall. 墙上没有地图。

结构 一般疑问句 be + there +主+其 
Is there a map on the wall? 墙上有地图吗？
 肯定与否定回答                   
Yes ,there is . No, there isn’t. 是的，有    不，没有
 特殊疑问句及回答  
特殊疑问词+ be +  —How many maps are there on the wall?
there +主+其它       墙上有多少张地图？
                            —There are two. 有两张
注1： There be 句型也可以由其它动词代替be，常用的词有seem to be , happen to be ,appear to be, used to be 等词组或用live, come, stand, lie, occur, exist, flow等动词。
There seems to be much hope of our team beating theirs.
好象我们队很有希望打败他们队。
Only there lived an old fisherman in a village by the sea.
从前有一位老渔夫住在海边的一个村子里。
注2： There be 之后如有几个并列主语时，用is或用are要取决于第一个主语是单数还有复数，单数用is,复数则用are.
There is a pen, a pencil and two books on the desk.
桌上有一支钢笔，一支铅笔和两本书。
There are two books, a pen and a pencil on the desk.
桌上有两本书，一支钢笔和一支铅笔。

【专项训练】
it的用法
1、“Do you like fish?”“Yes, I like         .”
 A．×   B．it  C．that   D．them
 2、         today?
 A．How is it     B．What is it
 C．What is it like      D．How is the weather.
 3、“Do you want a watch?”“         .”
 A．Yes, I want it .    B．Yes, I want one.
 C．No, I’ve got it.    D．No, I’ve got the watch.
 4、“Whose exercise-book is that?”
 “        hers”
 A．That is   B．This is  C．It’s    D．Its
 5、      won’t take long to get to Shanghai by air.
 A．That    B．He    C．It   D．This
 6、What he has done helps us a lot,           ?
 A．isn’t he    B．doesn’t he  C．isn’t it   D．doesn’t it
 7、We all thought       no use doing that.
 A．it     B．that   C．this   D．there
 8、I took it for granted        you would come to our party.
 A．when    B．why   C．for what  D．that
 9、How happy      to be able to study and live together with you!
 A．that will be   B．is it   C．will it be  D．it will be
 10、I thought it to be         .
 A．him    B．he   C．its   D．she
11、        very foolish of you to say so.
 A．It’s     B．Its   C．That’s   D．This
  12、It’s not his habit      for things.
 A．asks    B．ask   C．to ask  D．asked
 13、It has been a great honour       coming to visit me.
 A．they    B．you    C．she   D．he
 14、I found        to hear what he said.
 A．that difficulty      B．it difficulty 
 C．that difficult      D．it difficult
 15、He is fifty , but doesn’t         
 A．look at it        B．look for it
 C．look it        D．look him
 16、It was       who telephoned me yesterday.
 A．him   B．his    C．himself   D．he
 17、The sentence      is wrong.
 A．its    B．it    C．itself   D．it’s
 18、           is no doubt that he will succeed in his experiment.
 A．It    B．This   C．That   D．There
 19、It seems        John’s not coming after all.
 A．this   B．that   C．if   D．to
 20、      was a handbag that John gave Mary at Christmas.
 A．It    B．This   C．That   D．Such
 21、Was      the room       the famous writer had ever lived in?
 A．that, it   B．it , that  C．it , where  D．that, which
 22、        is said that he has been to many places in the United States.
 A．This   B．He    C．It    D．That
 23、What      you want me to do?
 A．it is    B．that   C．is this  D．is it that
24、Is      not important who will go?
 A．it   B．that   C．this   D．×
 25、Why is it       everyone thinks he’s a thief?
 A．because   B．as   C．when  D．that
26、          being Sunday, the library was closed.
 A．What   B．It    C．That   D．This
27、Is         believed       he is ill?
 A．it, that  B．he, that  C．it, if   D．he, for
28、         is known to us       Mary dances best.
 A．She, ×  B．It, that  C．It, she   D．She, who
29、“What’s this?”“       a flag.”
 A．This is   B．That’s  C．It’s    D．Its
30、Jack is ill. Have you heard about         ?
 A．him   B．it    C．this   D．that

There be 结构
31、Is      a typewriter in the room?
 A．he    B．there   C．it    D．has
32、There’s no one in the house, is           ?
 A．it    B．he     C．there  D．they
33、         must be something wrong.
 A．It    B．He     C．There  D．They
34、           there anyone around?
 A．Was   B．Were   C．There  D．Has
35、        used to be a church round the corner.
 A．Here  B．There   C．It    D．It is
36、It is reported that        is going to be a storm.
 A．it    B．there   C．×   D．the weather
37、There        still a lot of work to be done before the house is ready for occupation.
 A．are    B．were   C．is    D．have
38、There is a girl        for the bus.
 A．to wait  B．waiting   C．waited  D．wait
39、There         a pine tree at the top of the hill.
 A．stands   B．lies     C．lives   D．has
40、       will be a good film on at the Rex next week.
 A．There  B．It     C．That   D．This

改错,下列每句所给的选项中，各有一项是错的，请指出并改正。  
41、He is certain that the secretary will be there.
     A      B   C               D
42、I think that a good idea to get up early.
  A      B        C      D
43、It makes me feel sad that see you.
  A       B    C   D
44、Do you find it very dull live here?
   A     B     C     D
45、It is no use to cry over spilt milk.
    A B     C    D
46、There it must have been a mistake.
    A  B  C     D
47、There is going to have an English party at the weekend.
   A      B         C  D
48、Is there any one who waiting to see me ?
   A      B       C      D
49、There have a man sitting beyond that fence.
   A       B     C    D
50、It was a car ready for us.
  A  B    C   D
【答案】：
1、B  2、D  3、B  4、C  5、C  6、D  
7、A  8、D  9、D  10、A  11、A  12、C 
13、B  14、D  15、C  16、D  17、C  18、A
19、B  20、A  21、B  22、C  23、D  24、A
25、D  26、B  27、A  28、B  29、C  30、B
31、B  32、C  33、C  34、A  35、B  36、B
37、C  38、B  39、A  40、A  
41、A  He－it   42、B  that－it   43、C  that－to
44、D  live前加to  45、C  to cry－crying  46、B  it 去掉
47、B  have－be  48、C  who后加is 或把who去掉
49、A  have－is   50、A  It －There