it这个词在初中阶段出现频率比较高，用法也比较丰富，今天我们就来具体归纳总结一下初中阶段需要掌握的it的所有用法。
词性：代词（pron.）
一、代替前面提到过的事物或动物：
The apple is on the desk. Your mother put it there.
it指代前面说过的apple
The cat is very lovely. It is jumping here and there.
it指代前面说过的cat
二、用以明确身份：
Who is knocking at the door? It"s me.
It"s your mother on the phone.
三、指代婴儿，尤指性别不详的婴儿：
Who is the baby in the photo?
It is my younger brother.
四、 代替this和that：
What"s this?
It"s a bag.
五、形式主语：
此种方法比较重要，也相对复杂一些，是高频考点，我们来详细讲解一下。
（一）、形式主语的由来：
当不定式、动名词、从句等复杂成分（比较长）用作句子主语时，为保持句子平衡，避免头重脚轻，通常把真正的主语放在句末，而在句首使用形式主语it。
例如：在小区里和邻居融洽相处很重要。
Getting on well with neighbors in your neighborhood is very important.
主语很长，头重脚轻，因此引入形式主语it,真正的主语放到后面。
It"s important to get on well with neighbors in your neighborhood.
（二）、形式主语句型结构比较多，常见句型列举如下：
1、 It is adj./n. to do sth
1) It"s easy(adj) to recite words like this.这样背单词很简单。
2）It"s a waste(n.) of time to play computer games all day. 整天地玩
游戏很浪费时间。
3）As students, it is our duty to study hard.
作为学生，努力学习是我们的天职。
4）It is a pity that she failed in the exam again.
很遗憾，她考试又没有通过。
5）It is a good idea to go there by train.
坐火车去那儿是个好主意。
2、 It is of +n.(抽象名词) to do sth
of +n.(抽象名词)相当于前面所说的adj.
It’s important(adj.)to get on well with neighbors in your neighborhood.
=It’s of importance(n.)…写作的时候尝试使用一下，避免和别人的作文一样，千篇一律。
同样，it"s useful(adj.)…=it"s of use(n.)
It is useful to master more words to improve your English.
=It is of use to master more words to improve your English.
多掌握一些单词对于改善你的英语很有用。
3、 It is adj. for/of sb to do sth
这句话中sb叫做逻辑主语，是动作的实际发出者，前面有两个介词可选择，具体区分方法如下：
要根据形容词来决定
1) 如果adj.表示人的内在品质、性格特征，用of。
我们会发现，这样的adj.是可以用来修饰sb的，也可以理解成sb既是v.的主语，也是adj.的主语，通过汉语翻译我们也可以看出来
常见的这类形容词有kind, nice, brave, cruel, stupid, clever, wise等；
It"s brave of you to save the boy from the river.
你从河里把男孩救了现来你真勇敢。（brave主语是you, save的主语也是you）
2)除了以上情况，用for。
我们不难发现这样的形容词是不能用来修饰sb的，sb就只是v的主语
常见的这类形容词有easy, difficult, hard, important, impossible, possible, convenient 等等。
It is easy for you to help her.
对你来说帮助她很简单。（you是help的主语，但不是easy的主语，我们不能说you are easy,是吧）
4、It is time for sth=It is time to do sth 该做某事了。
It is time for dinner. It is time to have dinner.
5、It is time for sb to do sth 某人该做某事了。
It is time for me to do my homework.
6、It+v.+that+句子,that可以省略
1）It seems that you have finished the work.
看起来你完成工作了。
2）It appears that she doesn’t like this coffee.
看起来她不喜欢这个咖啡。
3）It doesn"t matter how much it is.
多少钱无关紧要。
4）It takes sb time to do sth 做某事花费某人多长时间
It took me two hours to repair this TV set.
修理这台电视我花费了两个小时。
5）It costs sb money to do sth 做某事花费某人多少钱
It cost me a lot of money to buy this camera.
买这台相机花了我好多钱。
7、It"s +动词过去分词+that+句子,that 可以省略
此句型中过去分词的主语不必提出来，但是有时为了翻译通顺，我们会加上主语，如“我们、大家”等等。
1）It is said many students lose themselves in the Internet recently. 据说最近许多学生沉迷于网络。
2）It is reported that the temperature will rise again tomorrow.
据报道明天气温会继续提升。
3）It is believed that she has tried her best.
我们相信她已经尽力了。
4）It is well known thatshe is a very good speaker.
众所周知，她是一名优秀的演讲者。
5）It must be realized that we don’t have much time to prepare for the coming examination.
我们必须意识到我们已经没有很多的时间准备即将来临的考试了。
6）It is considered right that students go to school without mobile phones.
大家认为学生上学不带手机是正确的
六、形式宾语：
与形式主语类似，当宾语较长时，it做为形式宾语先出现，真正的宾语放在后面。
find/think it adj to do sth
I found it easy to study English well.
我发现学好英语很简单。
She thought it important to study hard.
她认为努力学习很重要。
七、谈论时间、日期、距离、天气、气候、温度等时it作为主语：
It is already ten past ten.
It is May 6th today.
It is two kilometers from my school to my house.
It is very hot today.
链接重要句型：
It is/has been +一段时间+since+句子， 在这个句型中，it 代表时间
意思为："自从……以来已经多久了"
主句多采用一般现在时，从句用过去时。
It is three years since his father passed away.
他的爸爸去世三年了。
It has been a long time since she left here.
她离开这儿好长时间了。
八、强调句：
用以强调句子的某些成分(除了谓语动词)，写作利器哟。
It is +强调部分+that/who+其他
对人进行强调时用that和who都可以，对其他成分进行强调，只能用that
The teachers give us knowledge and care.
如果对主语进行强调：
It is the teachers who/that give us knowledge.
如果对knowledge and care强调
It is knowledge and care that the teachers give us.
九、习语或固定搭配：
1、That"s it. 原因就是这样
That"s it. I can’t put my heart into my study when you are so noisy.
原因就是这样，你这么吵，我无法全神贯注学习。
2、make it 两种汉语意思
1）约定在…
Let’s make it half past ten.
咱们定在十点半吧。
2）成功做到
Don’t worry. Keep trying and you are sure to make it.
别着急，坚持下去，你一定会成功的。
3、Believe it or not 信不信由你
Believe it or not. I will do as you said. 信不信由你，我会按照你说的做的。
4、Take it easy. 别着急，慢慢来It"s my turn
it九大用法是中考中的高频考点，同时形式主语的使用也是作文写作中的一个利器，一定要认真学习掌握哟。
原创，版权所有。
