It是代词，可以做形式主语和形式宾语。现就2009年高考英语试题中关于it试题来进行考点分析。
1.My friend showed me arround the town, ____ was very kind of him.(全国卷II，17)
A. which        B. that        C. where         D. it
2. Being a parent is not always easy, and being the parent of a child with special needs often carries with_____ extra stress.(北京卷，35)
A． it          B. them       C. one           D. him
3. _____ a certain doubt among the people ao to the practical value of the project.(安徽卷，32)
A. It has         B. They have   C. It remains     D. There remains
4. It is the first time that he has been to Australia, _____?(辽宁卷，34)
A. isn’t he       B. hasn’t he     C. isn’t it        D. hasn’t it
5. ---I have read another book this week.
---Well, maybe    is not how much you read but what you read that counts.(浙江卷，4)
A. this          B. that         C. there          D. it
答案与解析：
1.A。本题考查的是非限制性定语从句。which代表主句一句话所说的内容，如果是it则空前应该有and。
2.A。题意为：当父母并不总是那么容易，当一个有特殊需求的孩子的父母常常伴有特别的压力。空格处的代词应代指being the parent of a child with special needs这一动名词短语，所以用it。
3.D。题意为：关于这一项目的实用价值，人们还有某种怀疑。本题考查的是There be句型，be可用remain/lie/stand等来代替。出题人用It has 与there be句型混用考查来迷惑考生。
4.C。本题考查It’s the first/second…time that…固定句型，反问句需要根据It’s的变化。
5.D。本题考查的是It is + 被强调部分＋that ……。
考点分析：
一、It与定语从句的引导词混合考查。如：1题。
二、It与其他代词的词义辨析考查。如：2题
三、It is……的句型以及其反问句的考查。如：3和4题。
四、It is + 被强调部分 + that……的固定句式考查。如：5题。
备考策略：
1.分清非限制性定语从句和并列句的区别。试看下面两个句子：
He came late again, which made the teacher angry.
He came late again, and it made the teacher angry.
2.分清名词性从句和It句型的区别。
名词性从句的引导词在从句中要做成分，这类从句在句子中要做主语、宾语等；it做形式主语的句子后面一定有从句的引导词。如：
What worrries us most now is that he is still lying in hospital.
It worries him that his hair has become grey.
3.代词含义辨析。
it代指前文提到的物或事，“它”；that“那个”，指前文提到的同样东西或事情；one指前文提到的人或东西中的一个。如：
(1).There is a book on the desk and it is mine.
(2).We see when he comes to the town, and that is not often.
(3). ---Do you have a ruler?
--- Yes, I have a small one?
4.It is ……句型汇总分析
句         型        含    义        例         句
It is the first/second…time that + 现在完成时.        这是某人第一/二次做……。        It is the third time that we have been to
Beijing.
It was the first/second…time that + 过去完成时.        这是某人第一/二次做……。        It was the third time that we had been to Beijing.
It is time that + 过去时/should + v.        到了某人做……的时候了。        It is time that we had/ should have
Lunch.
It is time (for sb.) to do sth.         到了某人做……的时候了。        It is time for the students to have sports.
It is time for sth.        到了做……的时候了。        It is time for sports.
It is important/strange…for sb. to do sth.        某人做某事很重要/不可思议等。
        It is important for us to protect our
own environment.
It is clever/stupid…of sb to do sth.        某人做某事很聪明/笨等。        It is stupid of him to make such silly
mistakes.
It is n. that ….
        某人做某事是……。        It’s a good idea that we should have a football match.
It is one’s turn to do sth.        轮到某人做某事了。        It is your turn to be on duty.
It is important/necessary …that + should + v.        某人做某事很重要/不可思议等。        It’s important that we should take more exercise.
It is + v-ed that ….        人们认为某人做某事……。        It is expected that the National Games will take place successfully in Jinan.
It is + v-ed to v.        人们认为某人做某事……。
        The National Games are expected to
take place in Jinan.
It is + 被强调部分 +that….        强调句型。
        It is not until he came back that his father went to sleep.
Exercises：
I．单项选择：
1. The road conditions there turned out to be very good, ____ was more than we could expect.(08，全国卷II，16)
A. it           B. what        C. which          D. that
2. _____ was most improtant to her, she told me, was her family.(08，山东卷，23)
A. It           B. This         C. What          D. As
3. _____ is known to us all is that the 2008 Olympic Games will take place in Beijing.(08，福建卷，28)
A. It           B. What         C. As            D. Which
4. Isn’t it amazing how the humn body heals ____ after an injury?
A. himself      B. him          C. itself           D. it
5. Our neighbours gave ____ a baby bird yesterday that hurt ____ when it fell fron its nest.(08，湖南卷，21)
A. us; it        B. us; itself      C. ourselves; itself   D. ourselves; it
6. ---Have you heard the latest news?  
---No, What ________?(07，海南卷，全国卷I ，21)
A. is it         B. is there        C. are they         D. are those
7. I don’t mind her criticizing me,but    is how she does it that I object to.（07，福建卷，34）
A.it            B.that           C.this             D.which
8.The information on the Internet gets around much more rapidly than      in the newspaper.（07，辽宁卷，27）
A. it            B. those         C. one            D. that
9.---There is still a copy of the book in the library. Will you go and borrow
      ?
--- No, I’d rather buy         in the bookstore.(07,陕西卷，16)
A. it;one        B.one;one       C.one;it         D. it;it
10.      worries me the way he keeps changing his mind.（07，山东卷，24）
A. This         B.That           C. What          D. It
II．将下列句子翻译成英语：
1.我们保持身体健康很重要。
2.到了我们努力学习的时候了。
3.轮到我来照顾年迈的母亲了。
4.那是我第一次收到你的来信。
5.人们认为他的英语很棒。
答案：
I．1-5 CCBCB         6-10  AADAD
II．1. It is important for us to keep fit.
2.It is time for us to study hard./ It is time that we studied hard.
3.It is my turn to care for my old mother.
4.It is the first time that I have received your letter.
5.It is thought that he is good at English.