it做形式主语的用法大全
it做形式主语用法大全
It作形式主语常见句型动词不定式，动名词或主语从句作主语时，通常把它们放在谓语动词前，而用it作形式主语，放到句首，常见句型有：1. It + be + 形容词+主语从句，如：It is uncertain whether he can come to Jenny’s birthday party or not。
2。
It + be + 名词词组+ 主语从句，这类名词有：a fact，a pity，a shame，an honour，a question等，如：It’s a pity that you missed the exciting football match.It remains a question whether he will come or not.3。
It + be + 过去分词+ 主语从句，这类过去分词有:announced, believed，expected，hoped，decided, reported, said, shown等，如:It is reported that 16 people were killed in the earthquake。
It is not decided who will give the operation to the patient。
4。
It + 不及物动词（seem, appear, happen等) + 主语从句，这类不及物动词有:appear，happen，seem等，如：It seemed that he didn’t tell the truth.It happened that I was out when he called。
5。
It + be + 形容词+ for sb.）+ 动词不定式这类句型常用形容词easy, difficult，hard, important，possible，wise等作表语,有时候为了强调不定式动作的执行者，常在不定式前加for sb，如：It’s necessary for the young to master two foreign language。
it做形式主语时的用法
it做形式主语时的用法It作为形式主语时，常常用于代替后面真实主语的从句、动名词或不定式，以避免句子结构显得过于复杂或者不平衡。
以下是It 作为形式主语的几种常见用法：1、It + be + 形容词 + that从句：这种句型中的形容词通常是表示性格、品质的形容词，如nice、kind、stupid等。
例如：It is kind of you to help me. 你真好，帮了我。
2、It + be + 名词 + that从句：这种句型中的名词通常是表示时间、距离、度量衡等概念的名词。
例如：It is five years since we last met. 我们上次见面已经五年了。
3、It + be + 介词短语/副词 + that从句：这种句型中的介词短语或副词通常用来描述地点、方式等。
例如：It is in this room that we had the party. 我们就是在这个房间里开派对的。
4、It + be + 动词的过去分词 + that从句：这种句型中的动词过去分词通常是表示完成的动词，如known、heard、seen等。
例如：It is said that he has gone abroad. 据说他已经出国了。
5、It + be + 不定式短语/动名词 + that从句：这种句型中的不定式短语或动名词通常用来描述将来的动作或一般性的情况。
例如：It is to study hard that he will succeed. 他只有努力学习才会成功。
需要注意的是，在It作为形式主语的句子中，真正的主语通常是一个从句或非谓语动词短语，这些从句或短语被放在句子的后面，以保持句子的平衡和流畅。
(完整版)it做形式主语用法大全含练习及问题详解
It作形式主语常见句型动词不定式，动名词或主语从句作主语时，通常把它们放在谓语动词前，而用it作形式主语，放到句首，常见句型有：1. It + be + 形容词+主语从句，如：It is uncertain whether he can come to Jenny’s birthday party or not.2. It + be + 名词词组+ 主语从句，这类名词有：a fact, a pity, a shame, an honour，a question 等，如：It’s a pity that you missed the exciting football match.It remains a question whether he will come or not.3. It + be + 过去分词+ 主语从句，这类过去分词有：announced, believed, expected, hoped, decided, reported, said, shown等，如：It is reported that 16 people were killed in the earthquake.It is not decided who will give the operation to the patient.4. It + 不及物动词(seem, appear, happen等) + 主语从句, 这类不及物动词有：appear, happen, seem等，如：It seemed that he didn’t tell the truth.It happened that I was out when he called.5. It + be + 形容词+ for sb.）+ 动词不定式这类句型常用形容词easy, difficult, hard, important, possible，wise等作表语，有时候为了强调不定式动作的执行者，常在不定式前加for sb，如：It’s necessary for the young to master two foreign language.It is unwise to give the children whatever they want.这类形容词有：easy, difficult, hard, important, possible，wise6. It + be + 形容词+ of sb. + 动词不定式，这类形容词常是表示心理品质,性格特征的形容词，如：kind, nice stupid, clever, foolish, polite, impolite, silly, selfish, considerate等。
it用法大全形式宾语形式主语
2.非人称代词it
it有时并不指详细旳东西，而泛指天气、时间、环境等， 称为非人称旳it： 2.1.指天气： It is a lovely day, isn’t it? It is a bit windy.
2.2.指时间: It was nearly midnight when she came back.
用It作形式主语旳句型： (1) It is adj.＋ to do sth. It is difficult to translate this article.翻译这篇文章 极难。
(2) It is adj. ＋ for/of sb.＋ to do sth. It is important for us to learn English.学习英语对我 们很主要。
㈠ 1.it作人称代词
1.1.it旳最基本使用方法是作人称代词，主要指刚 提到 旳事物，以防止反复:
Ningbo is a beautiful city, isn’t it?
1.2.也能够指动物或婴儿(未知性别旳婴儿或孩子): Is this your dog？No, it isn’t.
1.3.也可指抽象事物: It was a great surprise to me when he did a thing like that．
2）.It is +v-ed +that 从句 ① It is said (reported， learned....) that ...
据说（据报道，据悉．．．）“。 It is said that he has come to Beijing.
= He is said to have come to Beijing.
②不论被强调部分是哪种状语，只能用 that连接，不得使用where、when等连词.
“it”作为形式主语的十大考点
“it”作为形式主语的十大考点1、It’s +形容词/名词+（for sb. / sth）+to do sth可以用于这类句型的形容词和名词以及例句如下：点击添加图片描述（最多60个字）2、It’s +形容词+of sb. +to do sth这个句型是同学们最容易丢分的，大家需要知道在这个句型中，形容词是描述人的品德、特征。
同学们看一下能用于这个句型的形容词和例句：点击添加图片描述（最多60个字）3、It’s +形容词/名词+doing sth在这个句型中，常见的形容词和名词有：no /little use, no /much good, useless等。
例如：It is no use crying over spilt milk.It is no good talking about other’s faults.4、It’s +形容词+that…能用于这个句型的形容词有：possible, important, impossible, necessary, strange, natural, surprising, obvious, true, likely, unusual等。
除了true, likely,obvious这三个词外，其他的词后面that从句一般要用虚拟语气，（should+动词原形）should可以省略。
大家看下面例句：点击添加图片描述（最多60个字）5、It’s +名词+that…在这个句型中，常用的名词有：fact, honor, belief, good thing / news, （no）wonder, no doubt, pity, shame等。
如例句1。
需要注意的是，在使用pity和shame的时候，从句一般用虚拟语气（should+动词原形），should可以省略。
意思是表示出乎意料“竟然”，如果没有这种意义的时候，就可以不用虚拟语气。
如例句2和3。
点击添加图片描述（最多60个字）6、It’s +及物动词的过去分词+that…这个句型中常见的及物动词的过去分词和例句如下：点击添加图片描述（最多60个字）7、It+不及物动词+that…能用于这个句型中的不及物动词常见的有：seem, happen, appear, matter等，例如：点击添加图片描述（最多60个字）8、It+及物动词+宾语+主语从句用于这类句型的动词有：affect, disappoint, impress, interest, worry等，例如：点击添加图片描述（最多60个字）9、It takes sb. + sometime to do sth.这个句型的意思是“花费某人多长时间做某事”例如：It took us half an hour to ride to the town by bike.10、It’s time (about time, high time ) +that…这个句型中that后面的从句要用虚拟语气，需要注意的是：常常用过去时态表示虚拟，有的时候也用should+动词原形，should不能省略。
关于It作形式主语的英语常见用法
关于It作形式主语的英语常见用法It 作形式主语代替主语从句，主要是为了平衡句子构造，主语从句的连接词没有变化。
而it引导的强调句那么是对句子某一部分进展强调，无论强调的是什么成分，都可用连词that。
被强调部分指人是也可用who/whom。
例如：It is a pity that you didn’t go to see the film.你没有去看这个电影，多可惜啊！It doesn’t interest me whether you sueed or not.对于你是否成功，我并不感兴趣。
It is in the morning that the murder took place.凶杀案发生的'时间是在早上。
It is John that broke the window.打碎窗户的是约翰。
(1)It is ＋名词＋从句It is a fact that … 事实是… It is an honor that …非常荣幸It is mon knowledge that …是常识It’s a pity tha t you missed the exciting football match.多么可惜啊，你错过了一场精彩的足球比赛。
(2)it is ＋形容词＋从句It is natural that… 很自然… It is strange that… 奇怪的是…It is uncertain whether he can e to Jenny’s birthday party or not.他来不来参加简的生日派对，这个不确定。
(3)it is ＋不及物动词＋从句It seems that… 似乎… It happened that… 碰巧…It seemed that he didn’t tell the truth.似乎他没有讲真话。
It happened that I was out when he called.碰巧，他打的时候我在外面。
it作形式主语的句型
it作形式主语的句型
1、It + be + 形容词 + that从句：表示某事物具有某个特征或属性。
例如：It is important that we arrive on time.（我们按时到达很重要。
）
2、It + be + 名词短语 + that从句：表示某个事物符合某个特征或属性。
例如：It is a shame that he didn’t come to the party.（他没来参加聚会真是遗憾。
）
3、It + be + 过去分词 + that从句：表示某个动作已经被完成或已经发生。
例如：It is said that the book will be published next month.（据说这本书将在下个月出版。
）
4、It + be + 现在分词 + that从句：表示某个动作正在进行或正在发生。
例如：It is raining hard outside.（外面正下着大雨。
）
5、It + be + 不定式短语 + that从句：表示某个动作将要发生或被计划。
例如：It is to be announced tomorrow if the meeting will be held as scheduled.（明天将宣布会议是否按计划举行。
）
这些句型中的“it”通常被称为“形式主语”，因为它在句子中充当主语，但实际上并不是真正的主语。
这种用法是为了使句子更加通顺或强调某种特定的信息。
It 作形式主语的基本用法
“It”作形式主语的基本用法基本含义：当不定式、动名词或从句在句子中作主语时，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。
It 作形式主语的常见句型：1) It is +adj.(+for sb./ sth.)+ to do sth.用于此句型的形容词有：easy, hard, difficult, possible, impossible, important, necessary, good, bad, exciting, interesting, surprising等。
例如：It was very hard for them to walk such a long way in the snow.他们在雪地里走那么远的路，真是太难了。
2) It is +n.(+for sb./ sth.) + to do sth.用于此句型的名词有：pity, shame, pleasure, one's duty, one's job, fun, joy, good manners, bad manners等。
例如：It is a pity for you to have missed such a wonderful play.你错过如此精彩的表演，太可惜了。
3）It is +adj. +of sb. + to do sth.此句型的形容词用于描述人的品质、特征等。
常见的有：kind, nice, friendly; silly, foolish, clever, wise; polite, impolite等。
例如：It is friendly of the family to try to make me feel at home in their house.这家人待我很好，让我有宾至如归的感觉。
形式主语的四种句型
形式主语的四种句型作为英语语法中重要的概念之一，形式主语在句子中所起的作用不可小觑。
它通常指代作为主语的一些短语，以便避免出现复杂的结构和重复过多的词语。
在句子中，形式主语的位置一般放在句首，可以是it，there，what以及whether。
接下来，我们将详细介绍四种典型的形式主语句型，并举例说明它们在日常交际中的应用。
一、以it为形式主语的句型1. It + be + 形容词 + (for someone) + to do something这种句型用于表达特定行为或事物对某人来说是容易或困难的，常用形容词有easy/hard, important/unimportant, convenient/inconvenient等。
例如：It is important for us to learn English well.(It 对应的是后面的不定式短语“to learn English well”)It is inconvenient for him to come here by bus.2. It + be + 名词 + to do something这种句型强调所作的行为或事情的性质和特点，常用名词有fact, truth,pity, shame, joy等。
例如：It is a fact that smoking is harmful to health.It is a shame to refuse help from a friend in need.3. It + be + 形容词 + that从句这种句型用于表达一种事实或假设情况的存在，以及所涉及的具体内容或状态，常用形容词有clear, evident, strange等。
例如：It is strange that he doesn't like chocolate.It is clear that the Internet has greatly changed our life.二、以there为形式主语的句型1. There + be + 名词 + (地点状语)这种句型常用于描述物品、人员、场所等存在的情况，常用名词有book, pen, people, hospital, school等。
it为形式主语的句型
it为形式主语的句型好吧，今天咱们聊聊“it” 这个小家伙，它可真是个灵活的角色，尤其在英语里。
你有没有注意到，很多时候我们说的东西其实就是在用“it”来引导，嘿，听起来是不是挺神奇的？比如说，“It’s amazing how time flies.” 这句其实是在说，时间过得飞快，难道不是吗？生活就像一场马拉松，有时候你会感觉自己跑得飞快，有时候又像是慢吞吞的乌龟，嘿，这就是人生的味道。
再说说天气吧，大家都喜欢聊天气，这也算是“it”登场的好时机。
“It’s raining cats and dogs” 这句话一出来，大家都知道外面下大雨了，完全不用担心。
天气变化无常，今天还是阳光明媚，明天可能就乌云密布，真是让人摸不着头脑。
不过嘛，大家也乐在其中，毕竟没有谁能预测明天的天气，简直就像在抽彩票一样，刺激又好玩。
还有那种“it”后面跟着形容词的句子，比如“It's important to stay positive.” 这句你听着可简单了，但其实蕴含了很多道理，保持积极的心态就像在逆风飞翔，虽然会有点辛苦，但那种飞翔的感觉，真是太爽了！生活中的小麻烦，像是一只只小虫子，咬咬你、烦烦你，但如果你能保持乐观，那简直就是在给这些虫子下最后通牒，嘿，别惹我，我可是有超级能力的！再说说学习，大家常说“it takes time to learn a language.” 是啊，学语言就像攀登高山，起初可能觉得步履维艰，但慢慢的，你会发现山顶的风景简直美得让人窒息！就像这段时间我在学做饭，起初弄得一团糟，连水饺都包不好，哈哈！但是渐渐地，竟然能做出一两道拿得出手的菜，心里那个美呀，简直能飘到天上去！说到做饭，不得不提“it’s fun to try new recipes.” 试着做一些新菜谱，真的是一场冒险！有时候会惊喜，有时候会崩溃。
想象一下，食材在锅里翻滚，香味四溢，结果一不小心，盐倒多了，哎，整碗汤咸得跟海水似的，但不管怎么样，做饭就是乐趣无穷的过程，每次做出新花样，心里都像开了一朵花。
it 做形式主语的句子结构
it 做形式主语的句子结构以it做形式主语的句子结构：1. It is believed that technology advancements have greatly improved our lives.2. It is crucial for businesses to invest in IT infrastructure to stay competitive.3. It is important to regularly update your software to protect against cyber attacks.4. It is necessary for IT professionals to have strong problem-solving skills.5. It is essential for companies to have a reliable IT support team to ensure smooth operations.6. It is beneficial for individuals to learn basic IT skills in today's digital age.7. It is recommended to back up your data regularly to prevent data loss.8. It is necessary to conduct regular IT audits to identify potential vulnerabilities.9. It is important to have a disaster recovery plan in place to minimize downtime in case of IT failures.10. It is crucial for businesses to prioritize cybersecurity toprotect sensitive information.It is believed that technology advancements have greatly improved our lives. From the invention of the wheel to the development of smartphones, technology has revolutionized the way we live, work, and communicate. With the rapid pace of innovation, it is imperative for businesses and individuals to embrace and adapt to these changes.It is crucial for businesses to invest in IT infrastructure to stay competitive. In today's digital age, technology plays a vital role in every industry. Whether it is managing customer data, streamlining operations, or enabling online transactions, a robust IT infrastructure is essential for businesses to stay relevant and meet the evolving needs of their customers.It is important to regularly update your software to protect against cyber attacks. With the increasing prevalence of cyber threats, software vulnerabilities are constantly being exploited by hackers. By keeping your software up to date, you can ensure that your systems are equipped with the latest security patches and protect yourself from potential attacks.It is necessary for IT professionals to have strong problem-solving skills. As technology continues to advance, IT professionals are faced with increasingly complex challenges. From troubleshooting network issues to resolving software bugs, having strong problem-solving skills is crucial in order to effectively address these issues and minimize downtime.It is essential for companies to have a reliable IT support team to ensure smooth operations. When technical issues arise, having a dedicated IT support team can make a significant difference in minimizing disruptions and resolving problems efficiently. Whether it is providing remote assistance or conducting on-site repairs, a reliable IT support team is essential in maintaining business continuity.It is beneficial for individuals to learn basic IT skills in today's digital age. As technology becomes more integrated into our daily lives, having basic IT skills is becoming increasingly important. From using productivity software to navigating online platforms, having a solid foundation in IT can enhance one's employability and enable them to fully participate in the digital world.It is recommended to back up your data regularly to preventdata loss. Data loss can occur due to various reasons such as hardware failure, accidental deletion, or malware attacks. By regularly backing up your data, you can ensure that your important files and documents are protected and can be easily restored in case of an unforeseen event.It is necessary to conduct regular IT audits to identify potential vulnerabilities. IT audits help businesses assess the effectiveness and security of their IT systems and identify any weaknesses or vulnerabilities. By conducting regular audits, businesses can proactively address any issues and implement necessary measures to enhance their IT infrastructure.It is important to have a disaster recovery plan in place to minimize downtime in case of IT failures. IT failures can occur due to various reasons such as natural disasters, hardware malfunctions, or cyber attacks. Having a well-defined disaster recovery plan can help businesses minimize downtime, restore operations quickly, and ensure business continuity.It is crucial for businesses to prioritize cybersecurity to protect sensitive information. With the increasing frequency and sophistication of cyber attacks, businesses must prioritizecybersecurity to protect their sensitive information and maintain the trust of their customers. This includes implementing robust security measures, conducting regular security audits, and providing cybersecurity training to employees.In conclusion, the role of IT in our lives and businesses cannot be overstated. From improving efficiency and productivity to protecting sensitive information, IT plays a vital role in today's digital age. By recognizing the importance of IT and investing in the necessary infrastructure and skills, individuals and businesses can fully leverage the benefits of technology and stay ahead in an increasingly digital world.。
英语语法：it用作形式主语的用法
英语语法：it用作形式主语的用法it用作形式主语的用法一、基本用法当不定式、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：Is it necessary to tell his father everything? 有必要把这个切都告诉他父亲吗?It’s no good sitting up too late. 熬夜没有好处。
It is quite clear that he has read the book. 很显然，他读过这本书。
It doesn’t matter what he says. 他说什么没关系。
二、几种特殊的形式主语(1) 用作动词look, seem, appear, happen, occur, follow等的主语(后接that从句或as if从句)：It seems as if it is going to rain. 看来要下雨了。
It seems that he knows everything. 他好像什么都知道。
It (so) happened that I had no money with me. 碰巧我没带钱。
From this witness it follows that he must be guilty. 根据该证人的证词判断，他一定有罪。
(2) 当系表结构后接有if 或when引出的状语从句时，通常在系表结构前使用形式主语表示说话人对某情况的看法：It was a great surprise to me when he did a thing like that. 他这样做使我很吃惊。
It would be a tragedy if anything went wrong. 如果出了什么事就是一个悲剧。
(3) 用于其他固定句型，如if it were not for…(若不是因为)，it’s time that…(该…了)等。
it做形式主语的19个句型
1.It is/was + 被强调部分+ that/who ...该句型是强调句型。
被强调部分可以是主语，宾语，表语或状语。
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。
2. It is 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 ...+(should) do 该句型和上一个同属一个句型。
it作形式主语的几大基本句型
it作形式主语的几大基本句型形式主语，顾名思义，即形式上是主语，但实际上不是真正的主语，真正的主语是后面的动词不定式、动名词或主语从句等。
如果让后面的动词不定式、动名词或主语从句用作主语，那么在句式上容易造成“头重脚轻”，句式不平衡，故往往用it作形式主语，而把真正的主语放在后面。
it在这里没有任何意义。
it作为形式主语常常用在以下几个句型。
◇It’s +形容词/名词+that +从句It is necessary that you train yourself before the walk.It is important that you have your own support team.It was a pity that he lost the game.It’s a pity that you missed the exciting football match.◇It’s +形容词+(for sb) +to do sthIt is difficult to walk through eight country parks.It is useful to have support teams.It is important for him to finish it in ten hours.It is necessary for people to learn team spirit.特别提醒：☆该句型的否定结构为It’s +形容词+(for sb) +not +to do sth It is very important not to give them too much food.It is very polite not to speak loudly in public.☆该句型有时可以与It is + adj. + that从句的句型互换使用，意思不变。
如：It is necessary for you to train yourself before the walk. = It is necessary that you will train yourself before the walk.◇It’s +名词+to do sthIt’s everyone’s duty to obey the law.It is not a good habit to stay up too late.As a student, it is bad manners to come late to class.It is my turn to clean the blackboard.◇It takes sb +some time to do sthIt took us two hours to set up the stage.◇It seems that +从句It seemed that he didn’t tell the truth.◇It’s +过去分词+从句惯用句型有：It is said that(据说), It is reported that(据报道), It is believed that(大家相信), It is hoped that(大家希望), It is well known that(众所周知), It is thought that(大家认为), It is suggested that(据建议)等。
it作形式主语形式宾语it开头的短语
D. when
7/5/2024
It 作形式主语 8. It + be + 名词或形容词 + 动名词， • 名词和形容词：good, no good, no use, a waste of,
useless, senseless, no hope, hopeless等 • It’s a waste of time talking to her any more. • It is no use arguing about the matter with him.
mountain on foot.
7/5/2024
练习题
1. In fact， D is a hard job for the police to keep order in an important football match.
A. this
B. that
C. there D. it
It + be + 名词词组（+ for sb.）+ 动词不定式
hoped, decided, reported, said, shown等。
• It is reported that 16 people were killed in the earthquake.
• It is not decided who will give the operation to the patient.
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以it开头的句型 2. it has been/is +一段时间+ since从句 It is six years since I began to work here. It has been six years since I worked here.
it作形主语的五种
it作形主语的五种IT 作为形式主语的五种情况如下：1. 结构：It + be/have/do + 名词/代词+ 形容词/副词/动词-ing/动词过去分词等形式。
例子：-It is said that he is going to join our team.（据说他将要加入我们的团队。
）-It has been raining since morning.（自从早上就一直下雨。
）2. 结构：It + 动词过去分词+ 名词/代词+ 形容词/副词等形式。
例子：-It seemed like a good idea at the time.（当时看来这是一个好主意。
）-It occurred to me that we had met before.（我想起来我们之前见过面。
）3. 结构：It + 动词-ing + 名词/代词+ 介词+ 宾语等形式。
例子：-It's interesting to learn about different cultures.（了解不同的文化很有趣。
）-It's important to keep the environment clean.（保持环境整洁很重要。
）4. 结构：It + 动词-ing/动词过去分词+ 副词等形式。
例子：-It's been a long time since we last met.（自从我们上次见面已经过去很长时间了。
）-It doesn't matter if he doesn't know.（他不了解没关系。
）5. 结构：It + 动词-ing/动词过去分词+ 宾语等形式。
例子：-It happened that I knew the person involved.（碰巧我知道涉及的那个人。
）-It occurred to me that I hadleft my wallet at home.（我想起来我把钱包忘在家里了。
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It作形式主语常见句型
四川省乐至中学张与刚
动词不定式，动名词或主语从句作主语时，通常把它们放在谓语动词前，而用it作形式主语，放到句首，常见句型有：
1.It+be+形容词+主语从句，如：
It is uncertain whether he can come to Jenny’s birthday party or not.
2.It+be+名词词组+主语从句，这类名词有：a fact,a pity,a shame,an honour，a question等，如：
It’s a pity that you missed the exciting football match.
It remains a question whether he will come or not.
3.It+be+过去分词+主语从句，这类过去分词有：announced,believed,expected, hoped,decided,reported,said,shown等，如：
It is reported that16people were killed in the earthquake.
It is not decided who will give the operation to the patient.
4.It+不及物动词(seem,appear,happen等)+主语从句,这类不及物动词有：appear, happen,seem等，如：
It seemed that he didn’t tell the truth.
It happened that I was out when he called.
5.It+be+形容词+for sb.）+动词不定式
这类句型常用形容词easy,difficult,hard,important,possible，wise等作表语，有时候为了强调不定式动作的执行者，常在不定式前加for sb，如：
It’s necessary for the young to master two foreign language.
It is unwise to give the children whatever they want.
这类形容词有：easy,difficult,hard,important,possible，wise
6.It+be+形容词+of sb.+动词不定式，这类形容词常是表示心理品质,性格特征的形容词，如：kind,nice stupid,clever,foolish,polite,impolite,silly,selfish,considerate等。
某人和这些形容词可以构成主系表结构。
如：
It’s very kind of you to help me with the work.
=You are kind to help me.
It seemed selfish of him not to share his dictionary with others.
=He seemed selfish not to share his dictionary with others.
7.It+be+名词词组+动词不定式，如：
It is not a good habit to stay up too late.
8.It+be+名词或形容词+动名词，这类名词和形容词常常是：good,no good,no use,
a waste of,useless,senseless等，如：
It’s a waste of time talking to her any more.
It is no use arguing about the matter with him.
9.It+take(sb.)+时间（金钱）+动词不定式，如：
It took the workers almost three years to finish building the dam.
It will take a whole day to get to the top of the mountain on foot.
实战演练：
1.It is generally considered unwise to give a child he or she wants.(NMET1997)
A.however
B.whatever
C.whichever
D.whenever
2.In fact is a hard job for the police to keep order in an important football match.
(2001上海)
A.this
B.that
C.there
D.it
3.is a fact that English is being accepted as an international language. (NMET1995)
A.There
B.This
C.That
D.It
4.Is necessary to take off our shoes when we enter the lab?(MET88)
A.everyone
B.this
C.her
D.it
5.________will take you a lot of time to find him in the crowd.
A.It
B.I
C.We
D.They
6.It is no use his_________there,the situation is hopeless now.
A.to go
B.to be going
C.going
D.having gone
7.It is never too late to learn,________?
A.is it
B.isn’t it
C.does it
D.doesn’t it
8.___________is known to all that Shenzhou VI Launched Successfully.
A.As
B.What
C.It
D.That
9._______is reported in the newspaper,the Earthquake in east China's Jiangxi Province killed13people
A.It
B.As
C.That
D.What
10.___________certain that his invention will make people’s life convenient.
A.That’s
B.This is
C.It’s
D.What’s
11._________that there is another football match on the air this evening.
A.It says
B.It was said
C.It is said
D.What was said
12.__________that their daughter got an opportunity to study abroad.
A.It’s a exciting news
B.This is an exciting news
C.This is exiting news
D.It’s exciting news
参考答案：
1——5BDDDA6——10CACAC11——12CD。