-2024届高考英语二轮复习it的用法讲义
文档属性
| 名称 | -2024届高考英语二轮复习it的用法讲义 |  | |
| 格式 | docx | ||
| 文件大小 | 38.6KB | ||
| 资源类型 | 教案 | ||
| 版本资源 | 通用版 | ||
| 科目 | 英语 | ||
| 更新时间 | 2024-04-09 18:49:29 | ||
图片预览
文档简介
It的用法
it是第三人陈单数主格或宾格，在句中可充当主语、宾语或表语。其用法可分“实指” it和“虚指” it及“句型结构词” it。
“实指” it it可具体地代替人、物或事情,有确定的意义 考点一 it用作代词 1. 用作人称代词 2. 用作非人称代词 3. it的词组
“虚指” it it表达的不是一个具体的人或事物，而是指笼统的一个概念
“句型结构词” it 用作形式主语或形式宾语的it及强调结构中的it 考点二：用作形式主语 考点三：用作形式宾语 考点四：it的固定句型 考点五：it用于强调句 it 指代时间的常用句型
一、it 作人称代词的用法（实指）
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. 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”。
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 是男孩还是女孩
There is a knock on the door. It must be the postman. 有人在敲门，一定是邮递员。
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. ” “这是什么 ”“是一种新机器”。
Nothing is wrong, is it 没出什么问题，是吗
it 作非人称代词的用法（虚指）
it 作非人称代词的用法，主要用于指时间、距离、价值、天气、气候及温度等自然现象。
(1)指天气。
Now it is clearing up, and a sparrow is beginning to chip. 现在天放晴了，一只麻雀开始喳喳叫起来。
It was a bitterly cold night and a ten o’clock it began to blow a gale.这是一个严寒之夜，十点钟狂风大作。
(2)指时间。
It's my birthday today. 今天是我的生日。
It's three years since I last saw her.三年没见到你了。
(3)指距离。
For one thing, it was a long journey to that part of the country.首先，要到那个国家的那个地方距离很远。
(4)指环境。
It'll be lovely in the garden tonight.今晚在花园里很不错。
(5)指一种形势或境况。
How's it going, Bob I haven't seen you for ages.鲍勃,情况怎样 我好久没有见到你了。
It can't be helped.没有什么办法。
It’s all over with me.我完全没有指望了。
(6)指笼统的情况。
All the people would have lost their lives if it hadn't been for the captain.要不是那位船长,船上所有的人都会丧生的。
I would have failed if it hadn't been for your help.要不是你的帮助我是会失败的。
it作一些动词或介词的宾语构成特定的词组。
make it (成功，做到), catch it(受罚) ,cool it (冷静下来) , have had it(全完了;没有希望了), rough it (过苦日子), forget it (别再想了，别提了) ,beat it (快跑;走开) , believe it or no (信不信由你) ,call it a day (停止做某事;收工)。接在介词之后的有:be for it(受罚) , ask for it(自讨苦吃), nun for it (拼命) , not a bit of it (一点儿也不)，As it is 照原样，Take it easy（不急） ，That’s it.（到此为止），It all depends（视情况而定）。that’s it.就是这样，get it理解，明白
句型结构词it
（一）it用作形式主语
为保持句子平衡，It 可以用在句首作为句子主语,而把句子的真正的主语移到后面去, 可以移到后面的主语是：不定式（短语）、动名词（短语）、从句。
It is important to know your limitations. 知道自己的局限性是很重要的。
It is fun working for him. 为他工作很有意思。
It is a wonder that he is still alive. 他居然还活着, 真是个奇迹。
(1) It + be + adj.+ for /of sb +to do sth 某人做某事……
It is hard for him to make up his mind. 他很难下定决心。
It was foolish of her to say such a thing. 她说那样的话，真是太蠢了。
说明：介词 of 与 for 的区别是：of 用于指某人的性格、属性、特征等，介词for表示对象，意为“对……来说”。
of 时此处 adj. 通常为描述人的属性、品德的形容词: kind, unkind，nice ,rude，cruel，considerate，thoughtful，careful，careless等。
for时此处adj. 通常为描述事件的形容词：easy，difficult，hard，necessary，unnecessary，possible，impossible，likely，unlikely，right，legal，illegal，polite，impolite，clear，obvious，dangerous…
It + be + n.+( for sb./sth.) +to do sth 某人做某事……是...
说明：常用于此句型的名词（短语）有：pity,shame,pleasure,fun,joy,good manners,bad manners
It is bad manners for the young to take up the seats for the old.
（2）It + be + 名词/形容词+ doing sth.
说明：常用于此句型的形容词和名词（短语）有：no /much good , no/little use ,no fun, useless ,worthwhile, senseless , a waste of time (money)…
It’s no use crying over the spilt milk.
It’s been a lot of fun meeting you.见到你很开心。
It is no use doing … 做…没用 It is useless doing sth… 做…没用 It is no good doing sth… 做…好处 It is a waste of time /money doing sth. 做...是浪费时间/钱。 It is fun doing sth. 做某事有趣。
（3） It be + ...+ 主语从句（is都可以换成was或其他变形）
①It be + 形容词+ that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 obvious that… …. 是显而易见的 It is true that… ……是真实的 It is natural that… …..是自然的 It is surprising that… …..是令人惊讶的 It is good that… ….是好的 It is wonderful that… ……是很棒的 It is funny that… …. 是有趣的 It is certain that… ……..是肯定的 It is probable that… …… 可能的 It is likely that… …… 可能的 It is possible that… …… 可能的 It is uncertain whether/if… ……..是还不确定的
②It be +名词词组+ that从句...
e.g. It is a pity that you can't come.
It is no wonder that... 难怪….. It is an honor that… 很荣幸…. It is a good thing that… ….是好事 It is a pity that… 很遗憾….. It is no surprise that… ….不令人惊奇 It is a shame that… ...真可惜 It is a fact that… 事实是... It is a wonder that.. 令人惊奇的是...
③It be +过去分词 + that从句...
e.g. It was said that the earthquake had caused a lot of damage.
It is suggested / required / ordered / insisted/… that sb. should do sth（据建议 / 有命令…）
It was ordered that we (should) arrive there in two hours.
It is said that... 据说….. It is believed that... 人们相信... It is suggested that... 有人建议... It is reported that… 据报道…. It is thought that … 人们普遍认为…. It is expected that… 期盼….. It is decided that.. 决定…. It is announced that.. 宣布…. It is arranged that… 安排…. It is well known that…. 众所周知…. It is acknowledged that… 公认的是….
④It be +不及物动词 + 主语从句...（所有加s都可以换成其他时态。）
It seems that… 看起来….. It happens that… 碰巧…. It matters that… ….关键；….起作用 It appears that… 看起来似乎…. It turns out that… 原来是…；结果是…. It proves that… 后来证明…；事实证明…. It occurs that… 碰巧…. It doesn’t matter whether/if... ...没关系 It seems as if… 看起来似乎…. It looks as if/as though… 看起来似乎…. 注意：as if引导的从句，如果与事实不相符合，则用虚拟语气。
⑤It be +及物动词+宾语 + that...
It occurs to sb. that…. 某人突然想起….. It comes to sb. that… 某人突然想出…. It strikes sb. that.. 某人突然想出…. It hits sb. that… 某人突然想出….
（4）It + took / will take (sb) + 时间段（或金钱）+ to do sth. 某人做某事花了……时间/钱。
It takes years to master a new language. 要花多年的时间才能掌握一门新的语言。
说明：此句型可以有以下多变种变体：It took me an hour to write the letter. =The letter took me an hour (to write). =I took an hour to write the letter. 我写这封信花了一个小时。
（二）it用作形式宾语
当不定式、动名词、从句等复杂成分用作宾语且其后跟有宾语补足语时，通常会在宾语补足语前使用形式宾语，而将真正的宾语移至句末。其基本结构为“动词+it+宾语补足语+不定式、动名词、名词性从句”。
He's made it a rule to see his parents once a week.他每周去见他的父母已成习惯。
We think it no use complaining.
I think it best that you should stay here.
主语+动词+it+宾补（adj./n.）+(for/of sb.)+真正的宾语（to do sth./从句）
说明：动词make/ think/ believe/find/consider认为/feel/imagine / regard / suppose/guess/notice/keep
主语+动词+it+宾补（adj./n.）+真正的宾语（doing sth.）
说明：宾补有useless/no use/no good
We think it important to learn a foreign language.
He considers it his duty to help those at risk.
I think it no use arguing with him.
The school has made it clear over and over again that smoking is
banned in the school.
某些及物动词或短语不能直接跟宾语从句，须先用it作形式宾语，然后接宾语从句，有此用法的：
主语+感情动词+it+if/when/that从句（在此句型中,it作形式宾语代替后而的从句）
说明：appreciate/enjoy/prefer/hate/love/like/dislike/mind
She won’t like it if you arrive late. 她不喜欢你迟到。
He hates it when people use his bike. 他讨厌别人用他的自行车。
I’d prefer it if I didn’t have to do so much work. 要是我不必做那么多工作，那就太好了。
I would appreciate it very much if you would help me with it. 如果你能帮助我做这事，我会十分感激。
说明：能用于此结构的动词还有have, take, put
Legend has it that Wu Song was buried at Hangchow.传说武松葬于杭州。
I take it (that) he will come on time. 我认为他会准时来的。
You can put it that it was arranged before. 你可以说这是以前安排的。
动词+介词+it+that从句。
说明：动词短语有rely/depend/count on（相信）, see to(确保)，answer for(负担，担保)，ask for(请求)，insist on, stick to。
See to it that you’re not late again. 注意千万不要再迟到。
Look to it that this doesn’t happen again. 注意不要再发生这种事。
You may rely on it that he’ll come to meet you. 你放心，他会来接你的。
I can’t answer for it that he will come. 我不能保证他会来。
动词+it+介词短语+that从句
I owe it to you that I am still alive. 多亏有你我才仍然活着。
I took it for granted that he would help us. 我认为他会帮助我们的。
说明：能用于此结构的动词不多，常见的有
take it for granted that...认为...理所应当
owe it to sb that...把...归功于某人
leave it to sb that...把...留给某人
keep it in mind that...把...记在心里
take it that…. 认为….；想… hate it when…. 讨厌…. like it when… 喜欢…. can’t help it if… 如果…,我也没办法 appreciate it if… 如果…将感激不尽 I don’t mind it if… 如果…我不介意 see to it that… 确保…;务必…. count on it that… 相信….. As someone puts it, ….. 像某人说的那样 If you don’t feel like it, …. 如果不喜欢,就…. When it comes to….., ….. 当谈到….. 主语+think/believe/ suppose/consider/feel/ make/keep/…. + it + useless/ no good / no use….+ doing sth. 某人认为……没用 主语+ think/believe/ suppose/consider/feel/ make/keep/…. + it + adj./ n. + for/of sb. + to do sth. 某人认为……怎样 I would appreciate it if you could ...（假如…，将不胜感激） see to / answer for / depend on / insist on it + that 从句（确保 / 对…负责 / 指望 / 坚持）
（三）it在特定句型中的运用
①It is up to sb to do sth. 该由某人做某事
It’s up to you to to make the choice. 得由你来作选择。
② If it were not for… / If it hadn’t been for… 若不是因为……
If it were not for your help, I would still be homeless. 若不是你帮忙，我现在还是无家可归。
③ It doesn’t matter…没关系
It doesn’t matter what he says. 他说什么都没关系。
④ (It is) no wonder( that) … 难怪…
It’s no wonder he is not hungry; he has been eating sweets all day. 难怪他不饿，他整天在吃糖果。
⑤It makes no/much difference 特殊疑问词 + 从句（不论…都没关系）
It’s doesn’t make much difference my being there. 我在不在那儿没有什么影响。
⑥ It’s one’s turn to do sth.
It’s my turn to clean the classroom. 是轮到我打扫教室的了。
⑦It never occurred to sb that +句子
It never occurred to me that they performed so well.
⑧It is convenient to/for sb
If it is convenient to you, please give me a hand tomorrow afternoon.
⑨主语 + make + it + a rule + to do / that从句 （定规矩；习惯于）
You need to make it a rule that these flowers should be watered once a week.
⑩when it comes to...当提到
When it comes to my choice, the top priority should be given to playing the piano.
Take it for granted that...
I took it for granted that he would help us. 我认为他会帮助我们的。
It is the same with...
Tom is very kind and can get on well with others.It is the same with his brother.
It remains to be seen whether / when /…从句 （有待证实）
e.g. It remains to be seen whether making a trip often does good to the old couple's health.
It (never) occurred to / came to / hit / struck sb. that… 某人（从没）想到…
It never occurred to me that you could succeed in persuading（说服） him to change his mind.
It is…when从句（当某事发生时，时间是在…）
It was 10 o’clock when they arrived at the village.
注意: when引导的是一个时间状语从句，主句中的it指时间。
How did it come about that +从句（…怎么发生的？）
主语 + make + it + clear + that从句（明确表示；阐明）
He made it clear that he totally agreed with what I said.他明确表示完全同意我所说的话。
as sb. put it... 正如某人所说...
（四）it用于强调句
1. It无意义，不可换成this/that. 2. be只用单数 is/was. 3. 强调句可对一个句子的主语、宾语、表语、状语进行强调，被强调的部分不能为谓语动词. 4. 强调的部分是人 也可用who其它一律用that.
①基本结构：It be + 被强调部分 +that /who +句子其他成分
②强调句的一般疑问句：Is/Was it +被强调部分+that/who+其他成分？
③强调句的特殊疑问句：特殊疑问词+is/was it +that/who+其他成分？
※：当强调句的特殊疑问词作宾语时，语序为：特殊疑问词+it is/was+that/who+其他成分.
e.g. I really don't know where it was that I put my wallet after I paid the bill.
④强调句的特殊结构：It is/was not until...that...
1. He didn't come back until the next year.
It was not until the next year that he came back.
2. They will not leave here until they finish the project.
It is not until they finish the project that they will leave here.
⑤复杂强调句型:It is/was +强调成分+ which/ when/ where等引导的定语从句+ that ...
It must have been here that I first met her.一定是在这儿我第一次和她见面。
It was not until I had lost it that I came to know its importance.直到失去了我才知道它的重要。
Who was it that called him “brother” 叫他“兄弟”的人是谁
What is it that you want me to do 你要让我做什么
Where was it that he spent his holidays 他是在哪里度假的呢
I don't know why it is that they don't like me.我不知道他们为什么不喜欢我。
It was in the factory where his father once worked that he found his job.他是在他爸爸曾经工作过的工厂找到了他的那份工作。
（五）it 指代时间的常用句型
1. It is (about /high ) time that sb. did /should do. 是做…. 的时候。
It is time + for sth.
It is time + (for sb.) to do sth. 到（某人）做某事的时候了。
It is the first ( second /last... ) time that sb. have /has done.第一次做……
It was the first ( second ... ) time that sb. had done
3.It is +时间段+ since + 从句后常用一般过去时 自从….以来有多久
It has been + 时间段+ since +从句（一般过去时）自从….以来有多久
It was +时间段+ since + 从句后常用过去完成时 在过去说“自从...以来有多长时间”
It + be + 时间段+ before+从句 （时态遵守主将从现或前后一致）
（肯定）过了多久才….
（否定）没过多久就…
It was / took + 一段时间 + before从句（过了…时间才…） It will be / will take + 一段时间 + before从句（要过…时间才…） It wasn’t / didn’t take + 一段时间 + before从句（没过…时间就…） It won’t be / won’t take + 一段时间 + before从句（过不了…时间就…）
After that it still took seven years before they got married.
I’m sorry to have kept you waiting, but it’ll still be some time before Brian gets back.
It didn’t take long before new trouble arose.
It won’t be long before we meet again.
it是第三人陈单数主格或宾格，在句中可充当主语、宾语或表语。其用法可分“实指” it和“虚指” it及“句型结构词” it。
“实指” it it可具体地代替人、物或事情,有确定的意义 考点一 it用作代词 1. 用作人称代词 2. 用作非人称代词 3. it的词组
“虚指” it it表达的不是一个具体的人或事物，而是指笼统的一个概念
“句型结构词” it 用作形式主语或形式宾语的it及强调结构中的it 考点二：用作形式主语 考点三：用作形式宾语 考点四：it的固定句型 考点五：it用于强调句 it 指代时间的常用句型
一、it 作人称代词的用法（实指）
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. 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”。
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 是男孩还是女孩
There is a knock on the door. It must be the postman. 有人在敲门，一定是邮递员。
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. ” “这是什么 ”“是一种新机器”。
Nothing is wrong, is it 没出什么问题，是吗
it 作非人称代词的用法（虚指）
it 作非人称代词的用法，主要用于指时间、距离、价值、天气、气候及温度等自然现象。
(1)指天气。
Now it is clearing up, and a sparrow is beginning to chip. 现在天放晴了，一只麻雀开始喳喳叫起来。
It was a bitterly cold night and a ten o’clock it began to blow a gale.这是一个严寒之夜，十点钟狂风大作。
(2)指时间。
It's my birthday today. 今天是我的生日。
It's three years since I last saw her.三年没见到你了。
(3)指距离。
For one thing, it was a long journey to that part of the country.首先，要到那个国家的那个地方距离很远。
(4)指环境。
It'll be lovely in the garden tonight.今晚在花园里很不错。
(5)指一种形势或境况。
How's it going, Bob I haven't seen you for ages.鲍勃,情况怎样 我好久没有见到你了。
It can't be helped.没有什么办法。
It’s all over with me.我完全没有指望了。
(6)指笼统的情况。
All the people would have lost their lives if it hadn't been for the captain.要不是那位船长,船上所有的人都会丧生的。
I would have failed if it hadn't been for your help.要不是你的帮助我是会失败的。
it作一些动词或介词的宾语构成特定的词组。
make it (成功，做到), catch it(受罚) ,cool it (冷静下来) , have had it(全完了;没有希望了), rough it (过苦日子), forget it (别再想了，别提了) ,beat it (快跑;走开) , believe it or no (信不信由你) ,call it a day (停止做某事;收工)。接在介词之后的有:be for it(受罚) , ask for it(自讨苦吃), nun for it (拼命) , not a bit of it (一点儿也不)，As it is 照原样，Take it easy（不急） ，That’s it.（到此为止），It all depends（视情况而定）。that’s it.就是这样，get it理解，明白
句型结构词it
（一）it用作形式主语
为保持句子平衡，It 可以用在句首作为句子主语,而把句子的真正的主语移到后面去, 可以移到后面的主语是：不定式（短语）、动名词（短语）、从句。
It is important to know your limitations. 知道自己的局限性是很重要的。
It is fun working for him. 为他工作很有意思。
It is a wonder that he is still alive. 他居然还活着, 真是个奇迹。
(1) It + be + adj.+ for /of sb +to do sth 某人做某事……
It is hard for him to make up his mind. 他很难下定决心。
It was foolish of her to say such a thing. 她说那样的话，真是太蠢了。
说明：介词 of 与 for 的区别是：of 用于指某人的性格、属性、特征等，介词for表示对象，意为“对……来说”。
of 时此处 adj. 通常为描述人的属性、品德的形容词: kind, unkind，nice ,rude，cruel，considerate，thoughtful，careful，careless等。
for时此处adj. 通常为描述事件的形容词：easy，difficult，hard，necessary，unnecessary，possible，impossible，likely，unlikely，right，legal，illegal，polite，impolite，clear，obvious，dangerous…
It + be + n.+( for sb./sth.) +to do sth 某人做某事……是...
说明：常用于此句型的名词（短语）有：pity,shame,pleasure,fun,joy,good manners,bad manners
It is bad manners for the young to take up the seats for the old.
（2）It + be + 名词/形容词+ doing sth.
说明：常用于此句型的形容词和名词（短语）有：no /much good , no/little use ,no fun, useless ,worthwhile, senseless , a waste of time (money)…
It’s no use crying over the spilt milk.
It’s been a lot of fun meeting you.见到你很开心。
It is no use doing … 做…没用 It is useless doing sth… 做…没用 It is no good doing sth… 做…好处 It is a waste of time /money doing sth. 做...是浪费时间/钱。 It is fun doing sth. 做某事有趣。
（3） It be + ...+ 主语从句（is都可以换成was或其他变形）
①It be + 形容词+ that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 obvious that… …. 是显而易见的 It is true that… ……是真实的 It is natural that… …..是自然的 It is surprising that… …..是令人惊讶的 It is good that… ….是好的 It is wonderful that… ……是很棒的 It is funny that… …. 是有趣的 It is certain that… ……..是肯定的 It is probable that… …… 可能的 It is likely that… …… 可能的 It is possible that… …… 可能的 It is uncertain whether/if… ……..是还不确定的
②It be +名词词组+ that从句...
e.g. It is a pity that you can't come.
It is no wonder that... 难怪….. It is an honor that… 很荣幸…. It is a good thing that… ….是好事 It is a pity that… 很遗憾….. It is no surprise that… ….不令人惊奇 It is a shame that… ...真可惜 It is a fact that… 事实是... It is a wonder that.. 令人惊奇的是...
③It be +过去分词 + that从句...
e.g. It was said that the earthquake had caused a lot of damage.
It is suggested / required / ordered / insisted/… that sb. should do sth（据建议 / 有命令…）
It was ordered that we (should) arrive there in two hours.
It is said that... 据说….. It is believed that... 人们相信... It is suggested that... 有人建议... It is reported that… 据报道…. It is thought that … 人们普遍认为…. It is expected that… 期盼….. It is decided that.. 决定…. It is announced that.. 宣布…. It is arranged that… 安排…. It is well known that…. 众所周知…. It is acknowledged that… 公认的是….
④It be +不及物动词 + 主语从句...（所有加s都可以换成其他时态。）
It seems that… 看起来….. It happens that… 碰巧…. It matters that… ….关键；….起作用 It appears that… 看起来似乎…. It turns out that… 原来是…；结果是…. It proves that… 后来证明…；事实证明…. It occurs that… 碰巧…. It doesn’t matter whether/if... ...没关系 It seems as if… 看起来似乎…. It looks as if/as though… 看起来似乎…. 注意：as if引导的从句，如果与事实不相符合，则用虚拟语气。
⑤It be +及物动词+宾语 + that...
It occurs to sb. that…. 某人突然想起….. It comes to sb. that… 某人突然想出…. It strikes sb. that.. 某人突然想出…. It hits sb. that… 某人突然想出….
（4）It + took / will take (sb) + 时间段（或金钱）+ to do sth. 某人做某事花了……时间/钱。
It takes years to master a new language. 要花多年的时间才能掌握一门新的语言。
说明：此句型可以有以下多变种变体：It took me an hour to write the letter. =The letter took me an hour (to write). =I took an hour to write the letter. 我写这封信花了一个小时。
（二）it用作形式宾语
当不定式、动名词、从句等复杂成分用作宾语且其后跟有宾语补足语时，通常会在宾语补足语前使用形式宾语，而将真正的宾语移至句末。其基本结构为“动词+it+宾语补足语+不定式、动名词、名词性从句”。
He's made it a rule to see his parents once a week.他每周去见他的父母已成习惯。
We think it no use complaining.
I think it best that you should stay here.
主语+动词+it+宾补（adj./n.）+(for/of sb.)+真正的宾语（to do sth./从句）
说明：动词make/ think/ believe/find/consider认为/feel/imagine / regard / suppose/guess/notice/keep
主语+动词+it+宾补（adj./n.）+真正的宾语（doing sth.）
说明：宾补有useless/no use/no good
We think it important to learn a foreign language.
He considers it his duty to help those at risk.
I think it no use arguing with him.
The school has made it clear over and over again that smoking is
banned in the school.
某些及物动词或短语不能直接跟宾语从句，须先用it作形式宾语，然后接宾语从句，有此用法的：
主语+感情动词+it+if/when/that从句（在此句型中,it作形式宾语代替后而的从句）
说明：appreciate/enjoy/prefer/hate/love/like/dislike/mind
She won’t like it if you arrive late. 她不喜欢你迟到。
He hates it when people use his bike. 他讨厌别人用他的自行车。
I’d prefer it if I didn’t have to do so much work. 要是我不必做那么多工作，那就太好了。
I would appreciate it very much if you would help me with it. 如果你能帮助我做这事，我会十分感激。
说明：能用于此结构的动词还有have, take, put
Legend has it that Wu Song was buried at Hangchow.传说武松葬于杭州。
I take it (that) he will come on time. 我认为他会准时来的。
You can put it that it was arranged before. 你可以说这是以前安排的。
动词+介词+it+that从句。
说明：动词短语有rely/depend/count on（相信）, see to(确保)，answer for(负担，担保)，ask for(请求)，insist on, stick to。
See to it that you’re not late again. 注意千万不要再迟到。
Look to it that this doesn’t happen again. 注意不要再发生这种事。
You may rely on it that he’ll come to meet you. 你放心，他会来接你的。
I can’t answer for it that he will come. 我不能保证他会来。
动词+it+介词短语+that从句
I owe it to you that I am still alive. 多亏有你我才仍然活着。
I took it for granted that he would help us. 我认为他会帮助我们的。
说明：能用于此结构的动词不多，常见的有
take it for granted that...认为...理所应当
owe it to sb that...把...归功于某人
leave it to sb that...把...留给某人
keep it in mind that...把...记在心里
take it that…. 认为….；想… hate it when…. 讨厌…. like it when… 喜欢…. can’t help it if… 如果…,我也没办法 appreciate it if… 如果…将感激不尽 I don’t mind it if… 如果…我不介意 see to it that… 确保…;务必…. count on it that… 相信….. As someone puts it, ….. 像某人说的那样 If you don’t feel like it, …. 如果不喜欢,就…. When it comes to….., ….. 当谈到….. 主语+think/believe/ suppose/consider/feel/ make/keep/…. + it + useless/ no good / no use….+ doing sth. 某人认为……没用 主语+ think/believe/ suppose/consider/feel/ make/keep/…. + it + adj./ n. + for/of sb. + to do sth. 某人认为……怎样 I would appreciate it if you could ...（假如…，将不胜感激） see to / answer for / depend on / insist on it + that 从句（确保 / 对…负责 / 指望 / 坚持）
（三）it在特定句型中的运用
①It is up to sb to do sth. 该由某人做某事
It’s up to you to to make the choice. 得由你来作选择。
② If it were not for… / If it hadn’t been for… 若不是因为……
If it were not for your help, I would still be homeless. 若不是你帮忙，我现在还是无家可归。
③ It doesn’t matter…没关系
It doesn’t matter what he says. 他说什么都没关系。
④ (It is) no wonder( that) … 难怪…
It’s no wonder he is not hungry; he has been eating sweets all day. 难怪他不饿，他整天在吃糖果。
⑤It makes no/much difference 特殊疑问词 + 从句（不论…都没关系）
It’s doesn’t make much difference my being there. 我在不在那儿没有什么影响。
⑥ It’s one’s turn to do sth.
It’s my turn to clean the classroom. 是轮到我打扫教室的了。
⑦It never occurred to sb that +句子
It never occurred to me that they performed so well.
⑧It is convenient to/for sb
If it is convenient to you, please give me a hand tomorrow afternoon.
⑨主语 + make + it + a rule + to do / that从句 （定规矩；习惯于）
You need to make it a rule that these flowers should be watered once a week.
⑩when it comes to...当提到
When it comes to my choice, the top priority should be given to playing the piano.
Take it for granted that...
I took it for granted that he would help us. 我认为他会帮助我们的。
It is the same with...
Tom is very kind and can get on well with others.It is the same with his brother.
It remains to be seen whether / when /…从句 （有待证实）
e.g. It remains to be seen whether making a trip often does good to the old couple's health.
It (never) occurred to / came to / hit / struck sb. that… 某人（从没）想到…
It never occurred to me that you could succeed in persuading（说服） him to change his mind.
It is…when从句（当某事发生时，时间是在…）
It was 10 o’clock when they arrived at the village.
注意: when引导的是一个时间状语从句，主句中的it指时间。
How did it come about that +从句（…怎么发生的？）
主语 + make + it + clear + that从句（明确表示；阐明）
He made it clear that he totally agreed with what I said.他明确表示完全同意我所说的话。
as sb. put it... 正如某人所说...
（四）it用于强调句
1. It无意义，不可换成this/that. 2. be只用单数 is/was. 3. 强调句可对一个句子的主语、宾语、表语、状语进行强调，被强调的部分不能为谓语动词. 4. 强调的部分是人 也可用who其它一律用that.
①基本结构：It be + 被强调部分 +that /who +句子其他成分
②强调句的一般疑问句：Is/Was it +被强调部分+that/who+其他成分？
③强调句的特殊疑问句：特殊疑问词+is/was it +that/who+其他成分？
※：当强调句的特殊疑问词作宾语时，语序为：特殊疑问词+it is/was+that/who+其他成分.
e.g. I really don't know where it was that I put my wallet after I paid the bill.
④强调句的特殊结构：It is/was not until...that...
1. He didn't come back until the next year.
It was not until the next year that he came back.
2. They will not leave here until they finish the project.
It is not until they finish the project that they will leave here.
⑤复杂强调句型:It is/was +强调成分+ which/ when/ where等引导的定语从句+ that ...
It must have been here that I first met her.一定是在这儿我第一次和她见面。
It was not until I had lost it that I came to know its importance.直到失去了我才知道它的重要。
Who was it that called him “brother” 叫他“兄弟”的人是谁
What is it that you want me to do 你要让我做什么
Where was it that he spent his holidays 他是在哪里度假的呢
I don't know why it is that they don't like me.我不知道他们为什么不喜欢我。
It was in the factory where his father once worked that he found his job.他是在他爸爸曾经工作过的工厂找到了他的那份工作。
（五）it 指代时间的常用句型
1. It is (about /high ) time that sb. did /should do. 是做…. 的时候。
It is time + for sth.
It is time + (for sb.) to do sth. 到（某人）做某事的时候了。
It is the first ( second /last... ) time that sb. have /has done.第一次做……
It was the first ( second ... ) time that sb. had done
3.It is +时间段+ since + 从句后常用一般过去时 自从….以来有多久
It has been + 时间段+ since +从句（一般过去时）自从….以来有多久
It was +时间段+ since + 从句后常用过去完成时 在过去说“自从...以来有多长时间”
It + be + 时间段+ before+从句 （时态遵守主将从现或前后一致）
（肯定）过了多久才….
（否定）没过多久就…
It was / took + 一段时间 + before从句（过了…时间才…） It will be / will take + 一段时间 + before从句（要过…时间才…） It wasn’t / didn’t take + 一段时间 + before从句（没过…时间就…） It won’t be / won’t take + 一段时间 + before从句（过不了…时间就…）
After that it still took seven years before they got married.
I’m sorry to have kept you waiting, but it’ll still be some time before Brian gets back.
It didn’t take long before new trouble arose.
It won’t be long before we meet again.