It的用法总结It的用法总结1.指代物，可替代动植物与无生命的东西，它与one的区别在于one= a/an+n.; it=the+n。
My father bought a pen and gave it(=the pen) to me.我爸爸买了一支笔并且把它给了我。
You can not eat your cake and have it．世事难两全。
I have no dictionary.So I want to buy one. (one=a dictionary)我没有字典，所以我想买一本。
I have a dictionary. It is over there.(it=the dictionary)我有一本字典。
它在那儿。
2.指代人it可指代未亲眼看到的，…不明身份性别的、面目不详的人，或婴儿．儿童，照片中的人物等。
--Who is crying in the room?--It's my brother Jack.一谁在房间里哭？一是我的兄弟杰克。
--Who is the girl in the photo on the wall?--It's my sister.一墙上照片里的女孩是谁？一是我的妹妹。
What a beautiful baby! Is it a boy? 一个多漂亮的宝宝啊！是男孩吗？There is a lady at the door. She wants to see you.门口有位女士。
她想要见你。
3.指代前述内容，或者是文中的内容。
Beauty is everywhere. It makes us happy.美随处可见。
这使得我们很快乐。
Mr. Wang was ill. Have you heard of it?王先生病了。
你听说了吗？4.指时间。
--What time is it by your watch?--It's ten minutes past two. --你的手表几点了? --2：10。
--What's the date today?--It's May lst.一今天几号？--5月1号。
(1) make it+时间：把时间定在…”；约定…“Let's make it eight o'clock.我们约在8点吧。
(2) It's time (for sb.) to do sth.该（某人）做…一的时候了。
It is time for us to set out.是我们该出发的时候了。
It is time for you to go to bed.你该上床睡觉了。
(3) It's time for sth.该做……的时候了It's time for lunch.=It's time to have lunch.该吃午饭了。
It's time for a break.=It's time to have a break.该休息了。
(4) It is/has been+时间+since…，自从……有多久的时间It's twenty years since she left me.自从她离开我已经有20年了。
(5)It was/will be+时间+before从句在多长时间后才发生某事It was twenty years before they met again.20年后他们才再次相遇。
5.指天气等自然现象It will snow heavily tomorrow.明天将会下大雪。
The volleyball match will be put off if it rains.如果下雨，排球赛将会被推迟。
6.指距离．速度、金钱、度量It's just two stops to the park.到公园只有两站路。
It is 90 dollars in price.价格90美元。
7.替代this或that--What's this/that? --这／那是什么？--It's my pencil sharpener. –我的卷笔刀。
That's not interesting，is it?没什么意思，对吗？8.作形式主语(1)替代动词不定式1) It is adj. (for sb.) to do sth.此结构中的形容词是描述事情的、说明句尾动词不定式特征的形容词。
It is good (for us) to eat vegetables.对我们来说吃蔬菜有好处。
2) It is+ adj.+of+sb. to do sth.本句型中的形容词一般表示人（逻辑主语）的某种特性，要么是夸赞，要么是贬损。
It is kind of you to lend me so many books.借我这么多书，你真的太好了。
It is wise of you to refuse his help.拒绝他的帮助你很明智。
3) It is a pity (for sb.) to do sth.很遗憾做某事．·It would be a pity to miss the opening ceremony.错过开幕式真是很遗憾。
4) It takes (sb.)+时间+to do sth.（某人）花了多少时间做某事It takes me halfan hour to walk from here to school.从这儿走到学校花了我半小时。
(2)替代动名词：动名词可以直接位于句首作主语，但为了强调，或动名词过长时，要用it 作形式主语置于句首，而把动名词放到句子最后。
1) It is nogood/use (in) doing sth.做……是没用的；做……是白费力气的It is no use crylng over spilt milk.覆水难收，悔恨无益。
It's no good getting angry with him.和他生气没有用2) It's fun doing sth.做……很有意思It's fun being a magician.做名魔术师很有意思。
(3)替代主语从句1) It+ be+ adj.+that从句It is clear that she is a thief很明显她是个小偷。
Is it true that you won the contest?你赢了比赛是真的吗？（4）It +be+名词或名词词组+that从句It is a pity that we have to leave tomorrow.很可惜我们明天不得不离开。
（5）It+ be+过去分词+that从句It is regarded that…人们认为……It is supposed that...人们猜测……；据推测……It is said that...据说……：有人说……It is pointed out that...有人指出……It is proposed that...有人提议……It is reported that...据报道…”It is stated that...据称……；据说……It is thought that...有人以为……；有人认为……It is well known that...众所周知……It is accepted that...人们公认……It is announced that...据称……；有人宣称…“It is believed that...有人相信……It is considered that...有人认为……It is mentioned that...据说……；上文提到…”It is said that the sports meeting will becalled off.据说运动会将被取消。
It is reported that Yao Ming got hurt while training.据报道姚明在训练中受伤了。
It is supposed that Tom will be our monitor next term.大家猜测汤姆下学期将会做我们的班长。
9.作形式宾语(1)主语+谓语动词+it+宾语补足语+(for/ofsb．)+不．定式／动名词／名词性从句：在这个句型中，谓语动词通常是find, think, make, consider, regard等。
引导名词性从句的有that,if,whether, who,what, when, where,how等。
I regard it important that we keep up with the times.我认为与时俱进非常重要。
I think it possible for us to get there on time if we hurry.如果快点的话，我认为我们准时到那儿是有可能的。
We all consider it wrong to cheat in examination.我们都认为考试作弊是不对的。
(2) it可以用在have, enjoy, hate, like, love, take, appreciate等动词后充当形式宾语。
We all take it that Liu Xiang will win the first prize.我们都相信刘翔会获得第一。
1 will appreciate it if you call me back.如果你给我回电话我会感激不尽。
10.没有实意的it：it常做seem, appear, happen, turn out等动词的主语，在这些结构中，it没有实意。
It seems unlikely that he will pass the exam.他不大可能会通过考试。
It happened that l was not in the classroom when the earthquake happened.地震发生时我碰巧不在教室。
It appears that she has many friends.她似乎有很多朋友。