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“it”的用法在高考中的运用作者：梁玉朋来源：《中学生英语·外语教学与研究》2017年第12期“it”作为一个小词在高考中频频出现。
因此，掌握该词的用法，摸清该词的考点至关重要。
本文从近年来全国各省高考英语试题中it考查点出发，总结了it的常考考点，旨在帮助学生掌握it的用法及其考点，进而提高英语知识运用能力。
1. it用作人称代词，代替前文提到的事物人称代词it主要指某样东西、某抽象事物，或者指不知性别的孩子、不明确身份信息的人。
此外，it还可以指时间、距离、天气等。
（张道真，2017）例如：Who’s that at the door？ It is the milkman. （2014年大纲卷，此处it代替上一句中的“在门口的那个人”。
）An average of just 18.75 cm of rain fell last year， making it the driest year since California became a state in 1850. （2014年浙江卷，此处it代替前文提到的last year。
）2. it作引导词，用作形式主语，代替不定式、动词-ing短语或从句表示的真正主语英语中有些句子头重脚轻，为了使得句子通顺协调，可以把it置于句首，用作形式主语，把真正的主语后移。
例如：The doctor thought it would be good for you to have a holiday. （2010年全国卷Ⅱ，此处it为形式主语，不定式to have a holiday作真正的主语。
）3. it作引导词，用作形式宾语，代替不定式、或从句表示的真正宾语这种用法多用于“某些动词+ it + adj./adv. +to do/that-clause”结构中，这些常见的动词有find/make/feel/consider/appreciate/bring等。
代词主标题：代词副标题：代词――特殊代词it重要度：4(共分5等)难度：4(共分5等)内容：特殊代词it：【定义】：人称代词it可以用来代替一个名词、一个短语、一个从句或一个句子，以避免它们在句中的重复。
这时它可以指提到过的，也可以指未提到过的，在句中作主语或宾语。
【it的用法】主要体现在以下几个方面：作为人称代词的it，非人称代词的it，指示代词it，形式代词it和it的一些固定用法。
例如：I love running. I t keeps me fit.（人称代词）It’s Sunda y tomorrow.（非人称代词表示气候、天气、温度、时间、地点、距离等或虚指的情境）Who’s it over there? It’s the milkman.（指示代词）It took me a week to recite the text.（形式主语）I think it my duty to help her.（形式宾语）It was in Shanghai that I first met Jack.（固定句型）【常考点】：1. it做形式主语或形式宾语。
It可以做形式主语或形式宾语，而把真正主语或宾语放在后面，真正得主语、宾语往往由从句、动名词、不定式充当。
1）It作形式主语常见结构有：It+be+形容词/名词+(for sb.) to do sthIt+be+形容词+(of sb.) to do sthIt+be+形容词/名词+ doing sthIt+be+过去分词+that从句It+be+名词（词组）+that从句It+be/seems(ed)+形容词+that从句It+ seems(ed)/appears(ed)/happens(ed) +that从句It doesn’t matter(It’s no wonder; It doesn’t make much difference等)+连接代词或连接副词引导的句子2）it作形式宾语的常见结构：主语+谓语+ it+形容词/名词/过去分词+从句常见谓语动词有think，find，prove，show，believe，consider，feel，imagine，make，regard，su ppose等例1：（14山东卷）Susan made______ clear to me that she wished to make a new life for herself.A．that B．thi s C．it D．her【答案】C。
入舵市安恙阳光实验学校高考英语一轮复习讲解：it的用法【知识要点】It的用法（一）作人称代词1、it代替前面（或后面）的单数名词或分句等所表示的事物。
e.g. You cannot eat your cake but have it.（it代替前面的cake）Although we cannot see it, there is air all around us. （it 代替后面的air）They say he has left town, but I don’t believe it. （it代替前面They…town分句中的情况）2、代替有生命但不能或不必分阴阳性的东西（包括婴儿）。
e.g. Yesterday we saw a big tree. It was fully twenty metres high. （it代替前面的tree）The baby cried because it was hungry. （it代替前面的baby）3、在某些习惯说法中，可以代替人。
e.g. ---- Someone is knocking at the door, Peter.---- Who is it?---- It’s me.---- Who are singing? ---- It is the children.---- The light is still on in the lab. It must be the third-year students doing the experiment.4、it与one的区别：这两个词都可以代表前面说过的名词，但it用于同名同物的场合；one则用于同名异物的场合。
e.g. ---- Do you still have the bicycle? ---- No, I have sold it.---- Is this knife yours? ---- No. It is Xiao Zhang’s. Mine is the one on the desk.5、it与that的区别：两词都可代替某一特定名词，但that指同一类，并非同一个。
高考英语语法知识之It 的用法总结1. It is + 被强调部分+ that ...该句型是强调句型。
将被强调的部分放在前面, 其它部分置于that之后。
被强调部分可以是主语, 宾语, 状语。
强调的主语如果是人, that可以由who换用。
如果把这种句型结构划掉后, 应该是一个完整无缺的句子。
这也是判断强调句型与其它从句的方法。
I.wa.the.tha.(who.cleane.th.classroo.yesterday.I.wa.i.th.stree.tha..me.he.father.2. It was not until + 被强调部分+ that ...该句型也是强调句型。
主要用于强凋时间状语，译成汉语＂直到．．．才．．．＂，可以说.no....unti....的强调形式. It was not until she took off her dark glasses that I realized she was a famous film star.= Not until she took off her dark glasses did I realize she was a famous film star...didn’.realiz.sh.wa..famou.fil.sta.unti.sh.too.of.he.dar.glasses.3. It is clear ( obvious, true, possible,certain....)that .....该句型中it 是形式主语, 真正的主语是that 引导的主语从句, 常译为＂清楚（显然, 真的, 肯定．．．）＂是主语从句最常见的一种结构。
It is very clear that he’s round and tall like a tree.= That he’s round and tall like a tree is very clear.4.I.i.importan..necessary.right.strange.natural....tha....由于主句中的形容词不同, tha.后的从句中要用虚拟语气（shoul..动词原形）, shoul.可以省去。
高考英语It的用法精讲一链接高考二主要内容1. 作人称代词或非人称代词2. 指无生命的东西或不详的性别3. 作形式主语4. 作形式宾语5. 用于强调句型中6. 用于几种特殊句式中三练一练一链接高考●主要形式：语法填空、写作等●考点：1. 作人称代词或非人称代词2. 指无生命的东西或不详的性别3. 作形式主语4. 作形式宾语5. 用于强调句型中（时态问题）6. 用于几种特殊句式中（特殊句式用于写作的积累）二·主要内容“It”的用法极其广泛,既可以作人称代词,也可以作非人称代词,表示时间、距离、气候等；既可以充当形式主语和形式宾语,也可以用于强调句结构中;它还常常用在某些动词或特殊词类之后,构成习惯用语。
下面就其使用的重点及难点,分门别类地加以总结。
1. 作人称代词,可以用来代替人、物或事；亦作非人称代词，表示时间、天气、季节、距离等。
It i s r aining c ats a nd d ogs. 雨下得很大。
It is a long way to the college. 大学距这儿很远。
It is eight o’clock sharp now. 现在是8点整。
2. 指无生命的东西，性别不详或性别无关紧要时，可用“It”来指动物，幼童等。
The baby cried because it was hungry。
小宝贝因为饿而哭了。
3. 作形式主语英语中不定式、动名词、主语从句在作主语时，主语往往显得很长，使整个句子看上去有点头重脚轻，这时就需要借助“It”作形式上的主语，而把整个句子的主语移到句子后边去，使句子看上去平稳一些。
It is difficult to study and work at the same time.一边工作一边学习很难。
It is very clear that the elephant's l eg is round a nd tall like a tree.大象的腿跟树干一样圆而高，这点显而易见。
高考英语it用法在高考英语中，“it”的用法是一个重要且常考的知识点。
掌握“it”的各种用法，对于提高英语成绩和语言理解能力有着至关重要的作用。
首先，“it”可以用作人称代词，指代前文提到过的事物或情况。
比如：“I bought a book yesterday It is very interesting”在这个句子中，“it”指代的就是前面提到的“book”。
“it”还常被用作非人称代词，表示天气、时间、距离、温度等。
例如，“It's sunny today”（天气）“It's five o'clock”（时间）“It's a long way from here to the station”（距离）“It's very cold”（温度）在强调句中，“it”的作用也十分突出。
强调句的基本结构是：“Itis/was ＋被强调部分＋ that/who ＋句子其他部分”。
通过这种结构，可以强调句子中的主语、宾语、状语等成分。
比如：“It was Tom who broke the window”强调的是主语“Tom”；“It was yesterday that I met him”强调的是时间状语“yesterday”。
“it”作形式主语也是高考中的常见考点。
当句子的主语过长，为了避免头重脚轻，通常会用“it”作形式主语，而把真正的主语后置。
常见的句型有：“It is ＋ adj ＋（for/of sb）to do sth”，例如：“It is important for us to learn English well” 还有“It takes sb some time to do sth”，像“It took me two hours to finish my homework”“it”作形式宾语的情况也不少见。
常见的结构为“find/think/consider/make ＋ it ＋ adj／n ＋to do/doing/that”，例如：“I find it difficult to learn math” 这里“it”代替了后面的“to learn math”，使句子结构更加平衡。
高考英语综合复习：考点透析“it的用法〞代词ita．用作人称代词，代替前文提到的事物b．代替指示代词this，thatc．表示时间、天气、距离、季节、明暗等引导词it it指时间时的重要句型a．It is(high) time(that) 主语+should do／did sth．It is(high) time that this problem was solved．b．It is…since…It is two years since he came to work in this city．c．It be…before…It will be three years before we can meet again．it 可做引导词，在句中做形式主语、形式宾语。
it 做形式主语的常用句型a．It is ／was＋adj.＋for／of sb．to do sth．It was difficult for her to move so heavy a box．b．It is／was＋adj．＋that…It was clear that he was lying to us．c．It is＋V～ed＋that…It is reported that our team has won the gold medal．d．It seems／appears／happens that…It seemed that he had known the truth．It so happened that I was standing at the gate when the guests arrived．e．It matters／doesn’t matter that…It matters a lot whether he will agree to our plan．f．It is no use／no good／no harm doing sth．It’s no good arguing with him．it 做形式宾语的常用句型(S代主语，V代谓语动词)a．S＋V＋it＋adj．／n．＋to do sth．We consider it a great honor to be able to host the 2008 Olympic Gamesb．S＋V＋it adj.／n．doing sth．They find it no use searching the empty house．Do you consider it any good trying again?c．主语＋谓语＋it＋that／when…I don’t like it when you shout at me．强调句：It is／was＋被强调成分＋who／that…如:如下句子中可对四处划线局部进展强调。
高三一轮复习I t的用法总结?It的用法在高考中也是重现率较高的语言点，尤其是it用于强调句。
其考查方式多通过“语法填空”进行，偶尔也出现在“短文改错”和“完形填空”中。
一、it 作人称代词的用法1. 指事物作为人称代词，it 可以除人以外的一切事物或动物。
如：I dropped my watch and it broke.It’s hard work, but I enjoy it.“Where is the dog?”“It’s in the bedroom. ”2. 指人it 指人主要用于指不性别不明的婴儿或用于确认某人的身份。
如：Is it a boy or a girl?There is a knock on the door. It must be the postman.【说明】在答语中，常用来指本人，如说It’s me。
3. 代替某些代词代词it 还可用于代替指示代词this, that 以及复合不定代词something, anything, nothing等。
如：“What’s this?”“It’s a new machine. ”Nothing is wrong, is it?二、it 作非人称代词的用法1. 基本用法：主要用于指时间、距离、价值、天气、气候及温度等自然现象。
如：It’s too late to go there now.It rained all day yesterday.It can get very hot here.2. 用于某些句型：It’s time for sb to do sth. 某人该干某事了。
It’s (about / high) time + that-从句. 某人该做某事了。
(从句谓语用过去式，有时也用“should+动词原形”)It’s first (second) time + that-从句. 某人第几次干某事。
(从句谓语用现在完成时)It’s + 时间段+ since-从句. 自从……有一段时间了。
高三一轮语法回顾与训练---It的用法和there be结构1.代词it常用来指代前文提到的事或物，还用在各种特殊句型中。
there be表示“存在”，可用在不同时态和句型中。
2.考点归纳一、it用法1. it用作形式主语（1）It + be + adj. + 主语从句It is clear（obvious / true / possible / certain…）+ that / whether…从句…It is essential（important / necessary / right / strange / natural…）+ that从句…（should + 动词原形）It is uncertain whether he can come to Jenny’s birthday party or not.It is important that we should learn English well.（2）It + be + 名词词组+ 主语从句It’s a pity that you missed the exciting football match.（3）It + 不及物动词（seem / appear / happen / turn out…等）+ 主语从句（看来/ 似乎/ 碰巧/ 证明是）It seemed that he didn’t tell the truth.It happened that I was out when he called.（4）It’s + adj. + for / of + sb. + to do sth特别注意：如何选择介词for 或of？如果该句型中的形容词是用来说明“某人”的性格或品质（如kind, good, nice, wise, stupid, clever, foolish, silly, impolite, selfish, considerate ...）时，介词用of（“某人”和这些形容词可以构成主系表结构），其它情况介词用for。
考点十五It的用法it作为代词用法非常灵活，可用于代替上文中提到的事物，代替上文中说到的一件事，代替不知情的人（尤其是不知身份、性别和姓名的人）。
也可用于表示时间、天气、距离、计算结果等。
还可用来代替不定式、动名词、从句等，充当形式主语或形式宾语。
一、用于指人以外的一切生物、无生命的东西和事情一般指说话者心目中已经了解或所指的生物、无生命的东西或事情，没有性别的区分；可以是可数名词，也可以是不可数名词，在句子中既可以作主语，也可以作宾语。
1. 指动物和植物。
☞ Look at that bird. It always comes to my window. 看看那只鸟。
它总是飞到我的窗前来。
2. 指代无生命的东西。
☞This is my watch. It’s made in Switzerland. 这是我的手表。
它是瑞士产的。
3. 代替上文提到过的整个事情。
☞Well, you mustn’t play on the road. It’s dangerous! 哦，你不能在马路上玩。
这是危险的！二、用于指代人1. 指代说话者心目中不太清楚的那个人，常在打电话或敲门时用。
☞—Who is knocking at the door? ——谁在敲门？—It’s me. ——是我。
2. 指说话者心目中的那个人。
☞—Look, someone is coming. Who can it be? ——看，有人过来了。
他可能是谁呢？—It may be the headmaster. ——可能是校长。
3. 在回答用指示代词表示人的特殊问句时，常用it指人。
☞—Who’s that? ——那人是谁？—Is it Helen? ——是海伦吗？—Yes, I think you’re right. It’s Helen. ——是的，我想你说对了，是海伦。
三、用于指时间、距离和自然现象等1. 表示时间。
☞—What’s the date? ——今天是几月几日？—It’s the third of March. ——今天是3月3日。
It的用法（专项总结及训练）一、人称代词1，it的最基本用法是作代词，主要指刚提到的事物，以避免重复:①They watched the train until it disappeared in the distance.2.，也可以指动物或婴儿(未知性别的婴儿或孩子):②Is this your dog？No, it isn’t.③They got a baby and it was a ten-pounder3.，也可指抽象事物或指抽象环境和情景:③I hate it when people talk with a full mouth.．二、.非人称代词1.it有时并不指具体的东西而泛指天气、时间、日期、距离、价值、度量、温度、环境等：⑴.指天气：It is a lovely day, isn’t it?⑵.指时间: It was nearly midnight when she came back.⑶.指日期:It is April First today.⑷.指距离:It is some 3000 kilometers from Beijing to Guangzhou.⑸.指价值:It is three dollars.⑹.指温度:Today it is 30 degrees centigrade.三、其他用法1.在句子的主语不太明确时充当主语，表示谁在做某事：①Who is it there? It's I (me/you/he.....).②I thought it was Mary, but it was not she.③Her face lighted when she saw who it was.2.泛泛的指某件事：(有时泛指一般情况)①It doesn’t matter.②It is a shame, isn’t it?③How is it going?(情况怎样)④It says in the newspaper that......3.指最好的或最渴望得到事物①He thinks he’s it. 他一直以为自己是最佳人选。
高考英语It的用法It是高考英语中一个极其重要的词，其用法多样，在不同的语境中具有不同的意义。
下面我们将从it的用法、句型和固定搭配三个方面进行讲解。
一、it用作实词1、表示时间、天气、距离、温度等自然现象。
例如：It is Monday today.今天是星期一。
It is raining outside.外面正在下雨。
It is 5 kilometers away from here.距离这儿有5公里远。
2、表示观点、看法、态度等主观想法。
例如：I think it is a good idea.我认为这是一个好主意。
We think it is important to learn English well.我们认为学好英语很重要。
二、it用作形式主语当不定式、动名词或从句作主语时，为了保持句子结构平衡，避免头重脚轻，常用it作形式主语，代替不定式、动名词或从句，而把真正的主语放在句尾。
例如：It is important to learn English well.学好英语很重要。
It took me an hour to finish the homework.我花了一个小时完成作业。
三、it用作形式宾语当不定式、动名词或从句作宾语时，为了保持句子结构平衡，避免头重脚轻，常用it作形式宾语，代替不定式、动名词或从句，而把真正的宾语放在句尾。
例如：I think it is important to learn English well.我认为学好英语很重要。
He found it hard to learn English well.他发现学好英语很难。
四、it用于强调句型中强调句型是英语中一个重要的句型，用于突出强调某个成分，特别是主语、宾语和状语等。
在强调句型中，it没有实际意义，只是起到引导作用。
例如：It is I who am the best student in my class.我是班里最好的学生。
高考英语语法知识之It 的用法总结1．It is + 被强调部分 + that ...该句型是强调句型。
将被强调的部分放在前面，其它部分置于that之后。
被强调部分可以是主语，宾语，状语。
强调的主语如果是人，that可以由who换用。
如果把这种句型结构划掉后，应该是一个完整无缺的句子。
这也是判断强调句型与其它从句的方法。
It was they that (who) cleaned the classroom yesterday. It was in the street that I met her father.2．It was not until + 被强调部分 + that ...该句型也是强调句型。
主要用于强凋时间状语，译成汉语＂直到．．．才．．．＂，可以说是 not ... until ... 的强调形式。
It was not until she took off her dark glasses that I realized she was a famous film star.= Not until she took off her dark glasses did I realize she was a famous film star.= I didn’t realize she was a famous film star until she took off her dark glasses.3．It is clear ( obvious, true, possible,certain....) that .....该句型中it 是形式主语，真正的主语是that 引导的主语从句，常译为＂清楚（显然，真的，肯定．．．）＂是主语从句最常见的一种结构。
It is very clear that he’s round and tall like a tree.= That he’s round and tall like a tree is very clear.4. It is important ( necessary, right, strange, natural...) that ...由于主句中的形容词不同，that 后的从句中要用虚拟语气（should + 动词原形），should 可以省去。
2014高考英语语法总结：It的用法（四）四、It 作形式主语的常见句型：1. 替代作主语的动词不定式，其句型为(1) It be adj. (for sb.) to do sth.此处adj. 通常为描述事件的形容词：easy, difficult, hard, necessary, unnecessary, possible, impossible, likely, unlikely, right, wrong, important, unimportant, legal, illegal, well-mannered, ill-mannered, polite, impolite, clear, obvious, certain, suitable, proper, fit, useful, useless, dangerous 例It is illegal (for a teenager) to drive a car without a license.(2) It be adj. of sb. to do sth.此处adj. 通常为描述人的形容词：kind, unkind, nice, rude, cruel, considerate, thoughtful, thoughtless, careful, careless, silly, foolish, stupid, clever, wise, crazy.例It’s kind of you to help me with the problem.(3) It替代作主语的动名词的常见句型It’s no good/use doingIt’s (well)worth doingIt’s (well)worth one’s while doing/to doIt’s (well)worth while doing/ to do例It’s no use crying over spilt milk.2. It替代作主语的从句常见句型(1) It is + noun +从句例It is no secret that the president wants to have a second term at office.(2) It is a dj. +clauseIt’s surprising that (should)竟然It’s a pity/shame that(should)竟然例It’s important that you should apologize to her for your rudeness.(=It’s of much importance that you should apologize to her for your rudeness.)(3) It verb sb. + clause= It is v-ing + clauseIt+surprise/delight/interest/disappoint/worry/disturb /annoy/amaze/bother/concern/frighten/please/anger sb. that 例It worried me that she drove so fast.(= It was worrying that she drove so fast.)(4) It verb (to sb.) that= sb/sth verb to do(verb = appear, seem, come about, emerge, follow, chance, happen, occur, transpire, turn out , work out)例It (so) happened/chanced that they were out.(= They happened/chanced to be out.)(5) It is v-ed that=sb/sth is to do(verb=say, report, think, believe, hope, expect, agree, accept, decide, determine, intend, plan, understand, know）例It is said that the couple have gotten divorced.(=The couple are said to have gotten divorced.)(6) It is v-ed that (should)(verb=demand, request, require,order, suggest, advise, recommend例It is suggested that they should begin with the third question.。
it的用法归纳it既可以用作代词，也可以用作引导词（作形式主语或形式宾语），还可以用来构成强调句型。
一、用作代词——这是it的基本用法。
1. 指事物-----指代上文或刚提到的事物，以避免重复。
I dropped my watch and it broke. 我把手表掉在地上摔坏了。
It’s hard work, but I enjoy it. 工作很辛苦，可是我乐意干。
—“Where is the dog?”—“It’s in the bedroom.”“狗在哪?”“在卧室里”。
Shanghai is a beautiful city, isn’t it?2. 指人-----指代未知性别的婴儿或身份不明确的人。
----Is this your dog？-----No, it isn’t.Is it a boy or a girl? 是男孩还是女孩?There is a knock on the door. It must be the postman.Someone is knocking at the door. Who can it be?【说明】在答语中，常用来指本人，如说It’s me。
3. 代替某些代词。
还可用于代替指示代词this, that 以及复合不定代词something, anything, nothing等。
如：“What’s this?”“It’s a new machine.”“这是什么?”“是一种新机器”。
Nothing is wrong, is it? 没出什么问题，是吗?4. 指抽象事物:It was a great surprise to me when he did a thing like that．You’ve helped me a lot. I shall never forget it.I tried my best to persuade him to give up smoking, but it didn’t help.[辨析] 代词it ,one 和that.（1）it代替的是前面提到的同一名称的同一事物，即同名同物。
秘籍09 it的代词用法和固定句型1.掌握it的代词用法1）用来指代前文中提到的东西。
既可指代具体的东西，也可指代一种情况。
2）也可以指动物3）用来指代人。
说明某人的身份或者做某事的人；指代婴儿或儿童；在不清楚某人性别时，也可使用 it，尤其在问答的形式中更为常见。
4） it有时并不指具体的东西，而泛指天气、时间、日期、距离、价值、度量、温度、环境等，称为非人称的it：2.掌握it 做形式主语1）It is + adj. + that 从句2）It is+ adj. ( for sb)+ to do3) It is+ adj. of sb. to do sth.3）It is + n + that 从句4）It is + ~ed+ that 从句5）It is+ adj. /n.+ to do2. it作形式宾语主语+think／believe ／make／find／consider／feel + it + adj. ／n.+ to do sth. ／V-ing／that从句3.It 用于强调结构中It is／was + 被强调的部分+ that +句子的其它部分4.掌握“it is/has been + 段时间+since…”和“It will be + 段时间+ before…”的考查特点1._________ happened ( so happened ) that he met his teacher in the street. 碰巧……2.__________is reported that another earth satellite has been put into orbit.3.—Who’s that at the door?—__________ is the milkman.4.—He got his first book published. It turned out to be a bestseller.—When was _____?—_____ was in 2000 when he was still in college.5.They found________ difficult that they would finish their work in two days.6.It is/has been fifteen years________ she left Shanghai.7.It was about 600 years ago _______the first clock with a face and an hour hand was made.【参考答案及解析】1.It 本题考查形式主语句型“ It happened /happens that ……（碰巧……）”2.It 本题考查形式主语句型,it 用来指代后面的that从句的内容。
高考英语一轮复习 it的用法讲解【知识要点】It的用法（一）作人称代词1、it代替前面（或后面）的单数名词或分句等所表示的事物。
e.g. You cannot eat your cake but have it.（it代替前面的cake）Although we cannot see it, there is air all around us. （it代替后面的air）They say he has left town, but I don’t believe it.（it代替前面They…town分句中的情况）2、代替有生命但不能或不必分阴阳性的东西（包括婴儿）。
e.g. Yesterday we saw a big tree. It was fully twenty metres high. （it代替前面的tree）The baby cried because it was hungry. （it代替前面的baby）3、在某些习惯说法中，可以代替人。
e.g. ---- Someone is knocking at the door, Peter. ---- Who is it? ---- It’s me.---- Who are singing? ---- It is the children.---- The light is still on in the lab. It must be the third-year students doing the experiment.4、it与one的区别：这两个词都可以代表前面说过的名词，但it用于同名同物的场合；one则用于同名异物的场合。
e.g. ---- Do you still have the bicycle? ---- No, I have sold it.---- Is this knife yours? ---- No. It is Xiao Zhang’s. Mine is the one on the desk.5、it与that的区别：两词都可代替某一特定名词，但that指同一类，并非同一个。
e.g. The climate of South China is mild（温和的）; I like it very much.（it指the climate of South China）The climate of South China is much better than that of Japan.（that指the climate）（二）作无人称代词it作无人称代词时，除了句中找不到它所代表的词语外，另一个特点是它后面的内容都是表示天气、时间、距离、度量衡及情况等。
It is fine (rainy, windy, etc.).It is noon.It is a half hour’s walk to the factor y.It is eighteen square metres in area.What does it matter?（三）作强调词，构成强调结构用以帮助改变句子结构，使句子的某一成分受到强调。
“It is (was) + 所强调的成分+ that (who) + 其它成分。
”在这个句型中，it本身没有词义。
注意: 在强调结构中，如被强调部分为时间状语或地点状语，其后的连接词也绝不能为when 或where，而应用that 。
在复习中，一定要注意句式的不同。
It was in Shanghai that I bought the guitar．(that引起强调句)It was Shanghai where I bought the guitar．(where引起定从It was twelve o'clock when we arrived there．(when引起时间状语从句）It was at twelve o'clock that we arrived there．（that 引起强调句）（四）引导词it作形式主语（宾语）为了使句子平衡，常采用形式主语（或宾语）it ，而把真正的主语（或宾语）置于句子后面。
通常引导词it与它所代替的句子成分中间要夹有某些词。
e.g. It takes half an hour to go there on foot.（It与to go there on foot之间夹有takes half an hour四个词）We thought it strange that Mr Smith did not come last night. （it与that从句中间夹有strange 但有时it与所替代部分之间并不夹有其它词。
e.g. You may depend on it that they will support you.（因为介词on之后一般不直接接that引导的宾语从句。
注意：it不是多余的，不能当作错句）（五）. it，one，that 的区别：作为代词，这三个词的对比使用是高考的热点之一。
---Why don't we take a little break? ---Didn't we just have __________?A．it B．that C．one D．thisThe Parkers bought a new house but _________will need a lot of work before they can move in．A．they B．it C．one D．whichone 用以指代同类事物中的任一，that 特指性强，指代可数与不可数词，而it指代上文提过的同一事物。
一、代词it用法例句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.这是一本新词学科网典，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用法例句k.Co m]主语代替不定式短语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。
用法例句形式宾语代替不定式短语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 ontime .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) + 其它强调部分例句说明主语It is I who am to blame. 是我该受责怪。
It w as 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。
状语时间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 tohelp 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。
【考点诠释】考点it的用法在英语中，运用it的场合较多。
