it作形式主语和形式宾语
“It”作形式主语和形式宾语的用法详解
新希望英语语法精讲—--—--“It"作形式主语和形式宾语“It"作形式主语和形式宾语的用法详解It作形式主语和形式宾语用法，是英语学习的主要语法项目之一。
无论是单项选择，还是完行填空，it 用法始终是反复考查的重、热点之一.现将it在特殊句型中作形式主语和形式宾语用法,进行如下归纳分析，以供学习参考。
一、It 用作形式主语当不定式（短语）、动名词(短语）或从句在某个句子中作主语时，为保持句子结构前后平衡,避免头重脚轻，因此常用it作形式主语置于句首，而将真正的主语放在句尾.此时it只起先行引导作用,本身无词义.e.g. It is wrong to tell a lie。
(说谎是错误的.) 〔It为to tell a lie的形式主语〕It is no use arguing about it. (争吵是没用的。
）〔It为arguing about it的形式主语〕It is uncertain who will come. (谁要来还不确定。
) 〔It为who will come的形式主语〕It 作形式主语的常见句型：①It + be + 形容词+ to do sth. / doing / that ….e。
g. It is very important to learn a foreign language. （学一门外语非常重要.)It is useless crying over the spilt milk。
（覆水难收.）It was really surprising that she married a man like that.(她嫁给那样的男士真让人惊讶。
)②It + be +名词词组+ doing / that ….e。
g。
It is no good telling lies. (撒谎没好处。
）It is a pity that you didn’t go to see the film yesterday. （你昨天没看成那部电影真遗憾。
英语语法it形式主语和形式宾语ppt课件
1 it 代替不定式（短语） 当不定式（短语）在复合宾语结构中作某些动词（如think, make, find,
consider, feel, suppose等）的宾语时。
I find it pleasant to work with him. They felt it my honor to be invited to speak here.
It
6.(改错)That felt funny watching myself on TV.
It
17
Summary
it
①It is+adj for/of sb+to do sth
作 代替不定式 ②It is+n+to do sth
为
③It takes/took sb+sth+to do sth
形
代替动名词 It is+no use/good/useless/pleasure/a wa
3
？ It is frightening to go climbing with him. to go climbing with him 是真正的主语
To go climbing with him is frightening.
通常it作为形式主语，在句中没有实 际意义，只是满足语法需要，起到 一个平衡句子结构，避免句子头重 脚轻的作用。
11
• ⑥ It + takes + (sb.) + some time + to do sth. •这是一个表示“（某人）花多少时间干某事”的 句型，其中it是形式主语，代替后面的不定式 （to do sth.），句型中的sb.也可以省略。
“It”作形式主语和形式宾语的用法详解
it作形式主语和形式宾语it既可作人称代词，用来表示动物或无生命的物体等，也可以作无人称代词，在句中作主语，表示“时间”、“距离”、“天气”等。
它还可以引导强调句，使语气得以加强。
此外，it在句中能作引导词，充当句子中的形式上的成分，如形式主语、形式宾语等。
㈠it作形式主语：it作形式主语时没有具体的意义，而只是帮助把真正的主语移到句子后部去，使句子显得平稳一些。
it作形式主语时，可以代替三种形式：不定式、动名词和主语从句。
1. it代替不定式短语常用于下列句型中：It + be +形容词+ (for/of sb.) to do sth.It + be + 名词+ to do sth.It takes sb. some time to do sth. 干…花了某人…时间It’s up to sb. to do sth. 干…是某人的职责或义务如：①It is everyone’s duty to obey the law.遵守法律是每个人的义务。
（it作形式主语, 代替不定式短语to obey the law）②It is difficult for a foreigner to learn Chinese.对于一个外国人来说，学习汉语是困难的。
（it作形式主语, 代替不定式短语to learn Chinese）③It is not right to use these places as rubbish dumps.把这些地方用来倒垃圾是不对的。
（it作形式主语, 代替不定式短语to use these places as rubbish dumps）④It took them a year to build the bridge.建这座桥花了他们一年的时间。
（it作形式主语, 代替不定式短语to build the bridge）⑤It is bad manners to stare at people.瞪着眼睛看人是不礼貌的。
It 用作形式宾语、形式主语
It 用作形式宾语当不定式（短语）、动名词（短语）或从句在某个句子中作宾语时,为保持句子结构平衡,避免句式结构的混乱,常用it作形式宾语,而将真正的宾语放在句尾.此时it仍只起先行引导作用,本身无词义.下列四种情况须用it 作形式宾语：●当不定式（短语）、动名词（短语）或从句在复合宾语结构中作某些动词的宾语时（如think,make,find,consider,feel,suppose等）；e.g.They found it pleasant that they worked with us Chinese.（他们发现与我们中国人一起工作很愉快.）I don’t feel it difficult to understand the Special English.（我觉得理解英语特别节目并不难.）He makes it a rule never to borrow money.（他立志决不向别人借钱.）I think it no need talking about it with them.（我认为没必要跟他们谈.）●某些表示“喜、怒、哀、乐”的动词,如like,enjoy,love,hate等,往往不能直接接宾语从句；e.g.I don’t like it that he’s so lazy.（我不喜欢他那么懒惰.）I hate it when my mother asks me to eat eggs.（我讨厌母亲要我吃鸡蛋.）●that引导的宾语从句不能直接作介词的宾语；e.g.You may depend on it that we shall always help you.（尽管放心,我们会随时帮你的.）Would you see to it that she gets home early?（你负责保证她早到家,好吗?）He insisted on it that he was innocent.（他坚持说自己是无辜的.）●由及物动词与介词组成的固定搭配中,宾语从句若作该动词的宾语时,须借用it.e.g.I leave it to your own judgment whether you should do it.（我让你自己判断这事是否该做.）We owe it to you that there wasn’t a serious accident.（多亏了你才没有发生严重事故.）“it”作形式宾语时的几种特殊结构英语中,当动词不定式、动名词或从句在句中充当宾语且其后又带有宾语补足语时,习惯上要在宾语补足语前使用一个没有具体意义的形式宾语it,而将真正的宾语移到补足语的后面,构成“动词＋it＋宾语补足语＋不定式（动名词或从句）”结构.如：She felt it her duty to take good care of them.她感到好好照顾他们是她的责任.I think it no good going there now.我认为现在去那里没有好处.The headmaster has made it clear that the school meeting will not be put off.校长说得很清楚校会不会推迟.但我们常会碰到it用作形式宾语时之后没有形容词或名词作宾语补足语的情况,这一点在近几年高考试题中经常涉及,需引起同学们的注意.I hate_____ when people talk with their mouths full.(NMET 1998)A.itB.thatC.theseD.them (答案为:A)我讨厌人们一边吃饭一边说话.I like _____ in the autumn when the weather is clear and bright.(全国卷2004)A.thisB.thatC.itD.one (答案为:C)我喜欢秋天晴朗的天气.以上这两道高考题中,it用作形式宾语,它的真正的宾语则是由when引导的从句.“it”的这种特殊用法常出现在以下几种结构中.A.动词＋it＋when / if 从句.常见于appreciate,enjoy,like,dislike,love,hate,prefer等少数动词之后.We would much appreciate it if you could do us that favour.要是你们能帮我们这个忙,我们将非常感激.I'd prefer it if I didn't have to finish the work.要是我不必完成那项工作,那就太好了.B.动词+ it + that从句.常见于like,take,have,put等少数动词之后（it相当于that从句的同位语）.I take it that they will succeed sooner or later.我认为他们迟早会成功的.The newspapers have it that some Japanese firms have gone bankrupt.报上说一些日本商号破产了.It 用作形式主语：1、当不定式（短语）、动名词（短语）或从句在某个句子中作主语时，为保持句子结构前后平衡，避免头重脚轻，因此常用it作形式主语置于句首，而将真正的主语放在句尾。
it作形式主语和形式宾语
It作形式宾语
1. find
consider
think
believe
+ it + adj./ n. + for sb. to do sth.
that 从句
feel
make
People felt it impossible for man to fly into outer space some years ago.
8. 他竟然那样举止不当, 似乎很奇怪. It seemed strange that he should have behaved like that. 9. 那天晚上他恰巧在那里.
It happened that he was there that evening.
10. 谁赢得这次竞选和我关系不大. It’ll make no difference to me who will win the election. 11. 他是否来都没关系.
I consider it a shame that we have lost the game.
用以上2个句型造句. 1.我认为他几乎每晚都出去散步是很奇怪的. I think it very strange that he goes out walking almost every night.
that 从句
It seems wise for us not to expect too much of him. It appears all right to tell him everything about it.
It seems true that he will take the place of Mr. Li. 4. It seems / appears (to sb.) that…
it作形式主语和形式宾语用法
it作形式主语和形式宾语用法2009-09-21 09:58:41| 分类：study | 标签：|字号大中小订阅一、It 用作形式主语当不定式（短语）、动名词（短语）或从句在某个句子中作主语时，为保持句子结构前后平衡，避免头重脚轻，因此常用it作形式主语置于句首，而将真正的主语放在句尾。
此时it只起先行引导作用 ...一、It 用作形式主语当不定式（短语）、动名词（短语）或从句在某个句子中作主语时，为保持句子结构前后平衡，避免头重脚轻，因此常用it作形式主语置于句首，而将真正的主语放在句尾。
此时it只起先行引导作用，本身无词义。
e.g. It is wrong to tell a lie.(说谎是错误的。
) 〔It为to tell a lie的形式主语〕It is no use arguing about it.(争吵是没用的。
) 〔It为arguing about it的形式主语〕It is uncertain who will come.(谁要来还不确定。
) 〔It为who will come的形式主语〕It 作形式主语的常见句型：①It + be + 形容词+ to do sth. / doing / that ….e.g. It is very important to learn a foreign language.(学一门外语非常重要。
)It is useless crying over the spilt milk.(覆水难收。
)It was really surprising that she married a man like that.(她嫁给那样的男士真让人惊讶。
)②It + be +名词词组+ doing / that ….e.g. It is no good telling lies.(撒谎没好处。
)It is a pity that you didn’t go to see the film yesterda y.(你昨天没看成那部电影真遗憾。
高中英语课件-it作形式主语及形式宾语句型
I would appreciate +it +if… 注意：表好恶的动词不能直接接宾语从句，
需要在从句前加上形式宾语it。
ห้องสมุดไป่ตู้
it的固定用法
When it comes to.... 当谈到…；
take it for granted that... 认为…理所当然
It is a fact(a pity, a shame, an honour，no wonder) +that从句 注：It is no good (use ) doing sth.(动名词短语做真正主语)
做某事是没益处(没有用的)的
注：区分常见的there be固定句型
There is no doubt that 毫无疑问 There is no need to do 没有必要 There is no point doing sth 做某事无意义
depend on it that...某人相信...
see to it that... 务必，保证
Let it be/go.
顺其自然；
That’s it. Make it. Get it.
对了，正是； 成功了； 懂了
一. it 用作形式主语 (1) It is+ adj. + that从句/to do sth
① It is clear, obvious,true,possible,certain.... that .....
“....是清楚（显然，真的，肯定）的” ② It is necessary, important, strange, natural.... that .....
“It”作形式主语和形式宾语用法详解
新希望英语语法精讲——-———“It"作形式主语和形式宾语“It”作形式主语和形式宾语的用法详解It作形式主语和形式宾语用法，是英语学习的主要语法项目之一。
无论是单项选择，还是完行填空，it 用法始终是反复考查的重、热点之一。
现将it在特殊句型中作形式主语和形式宾语用法，进行如下归纳分析，以供学习参考。
一、It 用作形式主语当不定式（短语）、动名词（短语）或从句在某个句子中作主语时，为保持句子结构前后平衡，避免头重脚轻，因此常用it作形式主语置于句首，而将真正的主语放在句尾。
此时it只起先行引导作用，本身无词义。
e.g. It is wrong to tell a lie. （说谎是错误的。
) 〔It为to tell a lie的形式主语〕It is no use arguing about it. (争吵是没用的.）〔It为arguing about it的形式主语〕It is uncertain who will come. (谁要来还不确定。
）〔It为who will come的形式主语〕It 作形式主语的常见句型:①It + be + 形容词+ to do sth. / doing / that ….e。
g。
It is very important to learn a foreign language. (学一门外语非常重要.)It is useless crying over the spilt milk。
(覆水难收。
)It was really surprising that she married a man like that。
（她嫁给那样的男士真让人惊讶。
）②It + be +名词词组+ doing / that …。
e。
g。
It is no good telling lies. （撒谎没好处。
)It is a pity that you didn’t go to see the film yesterday。
It 的用法
It 的用法1：it 做形式主语，不定式to do 或that 引导的句子做真正的主语例句: It is important for us to protect environment. 保护环境对我们来说是很重要的。
（it 做形式主语，真正的主语是to protect environment）即to protect environment is important for us 是本句，但这样显得头重脚轻，所以用it 做形式主语.例句: It is common knowledge that science and technology is the first productive force.( it 做形式主语，that 引导的句子做真正的主语2：it 做形式宾语，不定式to do 或that 做真正的宾语例句：He thinks it very hard to master a foreign language.他认为掌握一门外语是很难的。
（he 做主语，thinks 做谓语，it 做形式宾语，very hard 做宾补，to master a foreign language 做真正的宾语，即He thinks to master a foreign language very hard.例句：He thinks it very essential that he should have a decent job.他认为他应该有一份体面的工作是很必要的即He thinks that he should have a decent job very essential.3: it 用于强调句，其结构是it is \was+强调部分+that例句：It was his carelessness that caused his fatal failure.正是他的粗心导致了他的致命失败。
（强调his carelessness,做caused的主语,即强调主语）例句：It was in the cinema that I came across my former English teacher.在电影院我巧遇我的前任英语老师。
“It”作形式主语和形式宾语的用法详解
新希望英语语法精讲-————-“It”作形式主语和形式宾语“It”作形式主语和形式宾语的用法详解It作形式主语和形式宾语用法，是英语学习的主要语法项目之一.无论是单项选择，还是完行填空，it用法始终是反复考查的重、热点之一.现将it在特殊句型中作形式主语和形式宾语用法，进行如下归纳分析，以供学习参考.一、It 用作形式主语当不定式(短语）、动名词（短语）或从句在某个句子中作主语时，为保持句子结构前后平衡,避免头重脚轻，因此常用it作形式主语置于句首,而将真正的主语放在句尾。
此时it只起先行引导作用,本身无词义.e。
g。
It is wrong to tell a lie。
（说谎是错误的。
）〔It为to tell a lie的形式主语〕It is no use arguing about it. （争吵是没用的。
）〔It为arguing about it的形式主语〕It is uncertain who will come. （谁要来还不确定.）〔It为who will come的形式主语〕It 作形式主语的常见句型：①It + be + 形容词+ to do sth。
/ doing / that ….e。
g. It is very important to learn a foreign language。
(学一门外语非常重要.）It is useless crying over the spilt milk. （覆水难收.)It was really surprising that she married a man like that.(她嫁给那样的男士真让人惊讶。
）②It + be +名词词组+ doing / that ….e.g. It is no good telling lies. （撒谎没好处。
）It is a pity that you didn’t go to see the film yesterday。
It作形式主语和形式宾语
It作形式主语和形式宾语，虽然是我们高中就学过的语法点，但在考研英语题型中，无论是在阅读还是翻译，常会考查该知识点。
一、it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，这样就借助“it”来作形式上的主语，而把真正的主语移到句子后边去，使全句结构上前后平衡。
“it”并无实际意义。
It之后的谓语部分，可以是be+形容词，be+名词（词组），或be+过去分词等。
1．不定式做真正主语例句1：If you are part of the group which you are addressing, you will be in a position to know the experiences and problems which are common to all of you and it’ll be appropriate for you to make a passing remark about the inedible canteen food or the chairman’s notorious bad taste in ties. (2002 Text1)【结构分析】本句包含由and连接两个并列分句。
第一个分句主干为you will be in a position，不定式to know the experiences and problems 做定语，修饰position，其中which引导定语从句，修饰the experiences and problems。
第二个分句为it’ll be appropriate for you to …，其中it作形式主语，真正的主语为不定式to make a passing remark about…。
【参考译文】如果你是你谈话听众中的一员，你就能够了解你们所共有的经历和问题，而且你也可对餐厅极难吃的食物或者领导在选择领带方面差劲的品味进行评头论足。
it英语单词
it英语单词"it"是一个常用的英语代词，用于指代物体、动物或事物的性质、状态或情况。
以下是一些常见的用法：1.作主语：It is raining.（正在下雨。
）It is important to exercise regularly.（定期锻炼很重要。
）2.作宾语：I saw it at the store.（我在商店看到了它。
）Can you pass me the salt?I need it for the recipe.（你能给我递一下盐吗？我需要用来做菜。
）3.作形式主语或形式宾语：It is said that he will retire next year.（据说他明年将退休。
）I find it difficult to understand calculus.（我发现理解微积分很难。
）4.用于强调：It was John who broke the vase,not me.（打破花瓶的是约翰，不是我。
）It is I who am responsible for the project.（负责这个项目的是我。
）5.作引导词：It is clear that she doesn't want to come.（很明显，她不想来。
）It seems that they have already left.（看起来他们已经离开了。
）此外，"it"还可以用于表示时间、天气等方面的情况：-What time is it?（现在几点了？）-It is sunny today.（今天阳光明媚。
）请注意，"it"也可以指代婴儿（当性别未知或不重要时）：-It's a baby!（这是一个婴儿！）。
专题五：It作形式主语和形式宾语的用法
专题五：It作形式主语和形式宾语的用法一、It用作形式主语当从句、不定式、动名词等用作主语时，为避免头重脚轻，通常在句首使用形式主语it，而把真正的主语放在句子末尾。
1. 指代主语从句。
It is possible that he has stolen the car. 很可能他偷了小车。
It is strange that he should not have passed the test. 他测试没有通过真奇怪。
It is uncertain whether/if he will leave for Beijing tomorrow. 明天他是否去北京还不敢肯定。
2. 指代不定式（短语）作主语。
It is a pity to refuse. 拒绝是令人遗憾的。
It was his duty to attend to the matter. 处理这件事是他的责任。
It is impossible to finish the work on time. 准时完成工作是不可能的。
3. 指代动名词。
It is no good staying up too late. 熬夜是没有好处的。
It is no use saying anything more about it. 再说这件事没用。
It is useless crying over the spilt milk. 覆水难收。
It is a waste of time arguing with him. 与他争论简直是浪费时间。
It is a pleasure talking with you. 与你交谈真是件快乐的事情。
4. It用作形式主语的常用句型。
①It+is/was+形容词+to do sth./that…常见的形容词有known, clear, necessary, likely, unlikely, right, wrong, important, certain, obvious, strange, natural, kind, nice等。
it用作形式主语和形式宾语
it用作形式主语和形式宾语一、用作形式主语当不定式、动名词、从句等用作主语时，避免头重脚轻，通常在句首使用形式主语it，而把真正的主语放在句子末尾。
如：It is stupid to do such a thing. 做这种事真蠢。
It’s no good sitting up too late. 熬夜没有好处。
It is necessary that he should be sent there at once. 有必要马上派他到那里去。
注：类似以下句子中的it也可视为形式主语：It happened that the harvest was bad in 1988. 碰巧1988年的收成很不好。
It seems that she is afraid to tell them about it. 似乎她怕将此事告诉他们。
二、用作形式宾语当不定式、动名词、从句等用作宾语且其后跟有宾语补足语时，就应在宾语补足语前使用形式宾语，而将真正的宾语移至句末。
如：I’ve made it a rule never to hurry. 我已养成凡事从容不迫的习惯。
Do you think it possible to root out crime? 你认为可以根除犯罪吗?He found it difficult to breathe at high altitudes. 他觉得在高空呼吸困难。
注：通常意义的形式宾语主要见于真正宾语为不定式、动名词、从句等且其后跟有宾语补足语时的情形，即用于“动词+it+宾语补足语+真正的宾语”这样的结构，但以下两类形式宾语却比较特殊，其后没有宾语补足语：1、由于介词后通常不能直接跟that从句作宾语，有个别特殊结构就在介词后先接it作形式宾语，再跟that从句。
如：You may depend on it that it is true. 你可以相信这是真的。
I can’t answer for it that he will help you. 我不能保证他会帮你。
形式主语
浅谈it作形式主语和形式宾语用法It作形式主语和形式宾语用法，是中学阶段英语学习的主要语法项目之一。
纵观历届高考题，无论是单项选择，还是完行填空，it用法始终是反复考查的重、热点之一现将it在特殊句型中作形式主语和形式宾语用法，进行如下归纳分析，以供学习参考。
一、 It 用作形式主语当不定式（短语）、动名词（短语）或从句在某个句子中作主语时，为保持句子结构前后平衡，避免头重脚轻，因此常用it作形式主语置于句首，而将真正的主语放在句尾。
此时it只起先行引导作用，本身无词义。
e.g. It is wrong to tell a lie.(说谎是错误的。
) 〔It为to tell a lie的形式主语〕It is no use arguing about it.(争吵是没用的。
) 〔It为arguing about it的形式主语〕It is uncertain who will come.(谁要来还不确定。
) 〔It为who will come的形式主语〕It 作形式主语的常见句型：① It + be + 形容词+ to do sth. / doing / that ….e.g. It is very important to learn a foreign language.(学一门外语非常重要。
)It is useless crying over the spilt milk.(覆水难收。
)It was really surprising that she married a man like that.(她嫁给那样的男士真让人惊讶。
)② It + be +名词词组+ doing / that ….e.g. It is no good telling lies.(撒谎没好处。
)It is a pity that you didn’t go to see the film yesterday.(你昨天没看成那部电影真遗憾。
it作形式主语与形式宾语
i t作形式主语与形式宾语形式主语形式主语是动词的一种，它也是,可以把它归类到逻辑主语的第一种（不定式的逻辑主语）。
用作宾语的不定式，用作目的状语的不定式，用作结果状语的不定式都是属于不定式的大概念里面的。
详细用法综述形式主语it作为形式主语的it并无实际语义，只是为满足语法上的需要，避免句子头重脚轻，它代替的是句子的，概括起来会有如下情况：➢句子的逻辑主语为不定式如：It isverykindofyou togive meahandintime.It ismypleasure toaddress themeeting.It wasprettyhardforhim tobringup thechildonhisown.➢句子的逻辑主语为从句如：It sohappened that theticketsweresoldout.It isextremelyobvious that shehasbeenlyingaboutheridentity.It suddenlyoccurredtome that themessagemusthavebeenhiddenbetweenthelayersofthebriefcase.➢句子的逻辑主语为动名词短语这类句子远不如前面两种出现率高，主要在（nogood,waste,useless,nouse,dangerous）等词语的后面用。
如：It isnouse reasoning withhim.It isnogood reading indimlight.作形式主语的代词只能用it，不能用that、this等词。
例如:1）It iseasier tolose friendsthan tomake friends.交朋友难而失去朋友比较容易。
2）It isimportantformodernyoungpeople tomaster atleasttwoforeignlanguages.掌握至少两门外语对于当代年轻人来说是很重要的。
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it作形式主语和形式宾语it既可作人称代词，用来表示动物或无生命的物体等，也可以作无人称代词，在句中作主语，表示“时间”、“距离”、“天气”等。
它还可以引导强调句，使语气得以加强。
此外，it在句中能作引导词，充当句子中的形式上的成分，如形式主语、形式宾语等。
㈠it作形式主语：it作形式主语时没有具体的意义，而只是帮助把真正的主语移到句子后部去，使句子显得平稳一些。
it作形式主语时，可以代替三种形式：不定式、动名词和主语从句。
⒈it代替不定式短语常用于下列句型中：It + be +形容词+ (for/of sb.) to do sth.It + be + 名词+ to do sth.It takes sb. some time to do sth. 干…花了某人…时间It’s up to sb. to do sth. 干…是某人的职责或义务如：①It is everyone’s duty to obey the law.遵守法律是每个人的义务。
（it作形式主语, 代替不定式短语to obey the law）②It is difficult for a foreigner to learn Chinese.对于一个外国人来说，学习汉语是困难的。
（it作形式主语, 代替不定式短语to learn Chinese）③It is not right to use these places as rubbish dumps.把这些地方用来倒垃圾是不对的。
（it作形式主语, 代替不定式短语to use these places as rubbish dumps）④It took them a year to build the bridge.建这座桥花了他们一年的时间。
（it作形式主语, 代替不定式短语to build the bridge）⑤It is bad manners to stare at people.瞪着眼睛看人是不礼貌的。
（it作形式主语, 代替不定式短语to stare at people）⑥It is up to us to help those in need.帮助那些有困难的人是我们的责任。
（it作形式主语, 代替不定式短语to help those in need）⑦It is not up to you to tell me how to do my job.我怎样干我的工作不用你来多嘴。
（it作形式主语, 代替不定式短语to tell me how to do my job）◆It be + 形容词+ for sb. to do sth.与It be + 形容词+of sb. to do sth.：如果句型中的形容词描述的是sb.的品质、品格，在逻辑上可以作sb.的表语，则sb.前应用介词of，否则就用for。
如：①It’s necessary for us to use a short-wave radio to pick up the programmes.我们用一台短波收音机收听这些节目是必要的。
②It’s important for us to learn English well.学好英语对我们来说是重要的。
③It’s kind of you to help me.感谢你对我的帮助。
（= You are kind to help me. ）④It was foolish of him to give up the job.他放弃那工作是愚蠢的。
（= He was foolish to give up the job.）⒉it代替动名词短语：动名词作主语用后置形式的情况远不及不定式那么普遍，常限于no good, no use, useless, waste等词的后面。
①It is no good/ use having a car if you can’t drive.如果你不会开车，有车也没用。
( it作形式主语,代替动名词短语having a car)②It is a waste of time watching TV.看电视是浪费时间。
（it作形式主语,代替动名词短语watching TV）③It is no use asking him.问他没有用。
（it作形式主语,代替动名词短语asking him）④It is no use talking to him about it.和他谈这事没有用。
（it作形式主语,代替动名词短语talking to him about it）⒊it代替主语从句：这个主语从句可以用连词that引导，也可以用连接代词或连接副词引导。
如：①It was clear that they had no desire for peace.很清楚他们没有和平的诚意。
（it作形式主语,代替主语从句that they had no desire for peace）②It is doubtful whether she will be able to come.她能否来还很难说。
（it作形式主语,代替主语从句whether she will be able to come）③It was clear enough what she meant.她的意思是够清楚的。
（it作形式主语,代替主语从句what she meant）④It hasn’t been made clear when the new road is to be opened to traffic.还没明确宣布新路什么时候通车。
（it作形式主语,代替主语从句when the new road is to be opened to traffic）⑤It is a mystery to me how it all happened.这都是怎么发生的对于我来说还是一个谜。
（it作形式主语,代替主语从句how it all happened）用it作形式主语，把真正的主语从句移至后面的常见句型有：◆It is a pity/ a shame/ a fact/ an honour/ good news/ no wonder/ a wonder… that…如：①It was a pity that the engineer couldn’t come.可惜工程师没能够来。
②It is a wonder that he continues to gamble when he always loses!令人惊讶的是他一直输还一直赌。
③（It is）no wonder (that) you were late!难怪你来晚了。
④It is a shame that the rain spoiled our picnic.真可惜，这场雨把我们的野餐给搅了。
⑤It is a fact that English is being accepted as international language.英语被认为是国际语言，这是一个事实。
◆It is + 形容词（如：strange/ natural/ surprising/ obvious/ true/ fortunate/ wonderful/ funny/ possible/ impossible/ likely/ unlikely/ clear/ unusual/ certain/ important…）that …如：①It is certain that he will win.他一定会取胜。
②It is important that we should learn from each other and help each other.我们应当互相学习，互相帮助，这是很重要的。
③It was obvious that the child had been badly treated.很显然那个孩子受过虐待。
④It is likely that he will ring me tonight.他今晚可能给我打电话。
⑤It is strange that he should have left without telling us.真奇怪，他也没说一声就走了。
⑥It is unlikely that their group will get ahead of us.他们小组不会赶到我们前头去。
◆It seems/ happened/ turned out/ suddenly struck me/ occurred to me…that …如：①It happened that I wasn’t there that day.恰好那天我不在那里。
②It seems that his idea is more practical.看起来他的意见更实际一些。
③It suddenly occurred to me that I knew how to solve that problem.我忽然想起我知道怎样解决那个问题。
◆It + be + 过去分词（如：said/ reported/ announced/ decided/ expected/ hoped/ known/ believed…）that…如：①It is hoped that the number of deer will greatly increase very soon.(相当于：People hope that the number of deer will greatly increase very soon)人们希望鹿的数目将会很快增加。
②It is said that nothing has been done about it.据说至今对此没采取任何措施。
③It is reported that more than twenty people were killed in that bus accident.据报道在那次的公共汽车事故中有二十多人丧生。
④It is known that he is one of the best teachers in our school.大家都知道他是我们学校最好的教师之一。
⑤It is believed that the flood there is the biggest in 100 years.据认为那儿的洪水是百年来最大的洪水。
* 注意要在It is suggested/required/desired/ordered/proposed…that…的主语从句中用虚拟语气：(should) + 动词原形如：①It is requested that he give a performance at the party.有人请求他在聚会上表演一个节目。