it這個詞在初中階段出現頻率比較高，用法也比較豐富，今天我們就來具體歸納總結一下初中階段需要掌握的it的所有用法。
詞性：代詞（pron.）
一、代替前面提到過的事物或動物：
The apple is on the desk. Your mother put it there.
it指代前面說過的apple
The cat is very lovely. It is jumping here and there.
it指代前面說過的cat
二、用以明確身份：
Who is knocking at the door? It's me.
It's your mother on the phone.
三、指代嬰兒，尤指性別不詳的嬰兒：
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、形式主語：
此種方法比較重要，也相對複雜一些，是高頻考點，我們來詳細講解一下。
（一）、形式主語的由來：
當不定式、動名詞、從句等複雜成分（比較長）用作句子主語時，為保持句子平衡，避免頭重腳輕，通常把真正的主語放在句末，而在句首使用形式主語it。
例如：在小區裡和鄰居融洽相處很重要。
Getting on well with neighbors in your neighborhood is very important.
主語很長，頭重腳輕，因此引入形式主語it,真正的主語放到後面。
It's important to get on well with neighbors in your neighborhood.
（二）、形式主語句型結構比較多，常見句型列舉如下：
1、 It is adj./n. to do sth
1) It's easy(adj) to recite words like this.這樣背單詞很簡單。
2）It's a waste(n.) of time to play computer games all day. 整天地玩
遊戲很浪費時間。
3）As students, it is our duty to study hard.
作為學生，努力學習是我們的天職。
4）It is a pity that she failed in the exam again.
很遺憾，她考試又沒有通過。
5）It is a good idea to go there by train.
坐火車去那兒是個好主意。
2、 It is of +n.(抽象名詞) to do sth
of +n.(抽象名詞)相當於前面所說的adj.
It’s important(adj.)to get on well with neighbors in your neighborhood.
=It’s of importance(n.)…寫作的時候嘗試使用一下，避免和別人的作文一樣，千篇一律。
同樣，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.
多掌握一些單詞對於改善你的英語很有用。
3、 It is adj. for/of sb to do sth
這句話中sb叫做邏輯主語，是動作的實際發出者，前面有兩個介詞可選擇，具體區分方法如下：
要根據形容詞來決定
1) 如果adj.表示人的內在品質、性格特徵，用of。
我們會發現，這樣的adj.是可以用來修飾sb的，也可以理解成sb既是v.的主語，也是adj.的主語，通過漢語翻譯我們也可以看出來
常見的這類形容詞有kind, nice, brave, cruel, stupid, clever, wise等；
It's brave of you to save the boy from the river.
你從河裡把男孩救了現來你真勇敢。（brave主語是you, save的主語也是you）
2)除了以上情況，用for。
我們不難發現這樣的形容詞是不能用來修飾sb的，sb就只是v的主語
常見的這類形容詞有easy, difficult, hard, important, impossible, possible, convenient 等等。
It is easy for you to help her.
對你來說幫助她很簡單。（you是help的主語，但不是easy的主語，我們不能說you are easy,是吧）
4、It is time for sth=It is time to do sth 該做某事了。
It is time for dinner. It is time to have dinner.
5、It is time for sb to do sth 某人該做某事了。
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.
看起來你完成工作了。
2）It appears that she doesn’t like this coffee.
看起來她不喜歡這個咖啡。
3）It doesn't matter how much it is.
多少錢無關緊要。
4）It takes sb time to do sth 做某事花費某人多長時間
It took me two hours to repair this TV set.
修理這臺電視我花費了兩個小時。
5）It costs sb money to do sth 做某事花費某人多少錢
It cost me a lot of money to buy this camera.
買這臺相機花了我好多錢。
7、It's +動詞過去分詞+that+句子,that 可以省略
此句型中過去分詞的主語不必提出來，但是有時為了翻譯通順，我們會加上主語，如「我們、大家」等等。
1）It is said many students lose themselves in the Internet recently. 據說最近許多學生沉迷於網絡。
2）It is reported that the temperature will rise again tomorrow.
據報導明天氣溫會繼續提升。
3）It is believed that she has tried her best.
我們相信她已經盡力了。
4）It is well known thatshe is a very good speaker.
眾所周知，她是一名優秀的演講者。
5）It must be realized that we don’t have much time to prepare for the coming examination.
我們必須意識到我們已經沒有很多的時間準備即將來臨的考試了。
6）It is considered right that students go to school without mobile phones.
大家認為學生上學不帶手機是正確的
六、形式賓語：
與形式主語類似，當賓語較長時，it做為形式賓語先出現，真正的賓語放在後面。
find/think it adj to do sth
I found it easy to study English well.
我發現學好英語很簡單。
She thought it important to study hard.
她認為努力學習很重要。
七、談論時間、日期、距離、天氣、氣候、溫度等時it作為主語：
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.
連結重要句型：
It is/has been +一段時間+since+句子， 在這個句型中，it 代表時間
意思為："自從……以來已經多久了"
主句多採用一般現在時，從句用過去時。
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.
她離開這兒好長時間了。
八、強調句：
用以強調句子的某些成分(除了謂語動詞)，寫作利器喲。
It is +強調部分+that/who+其他
對人進行強調時用that和who都可以，對其他成分進行強調，只能用that
The teachers give us knowledge and care.
如果對主語進行強調：
It is the teachers who/that give us knowledge.
如果對knowledge and care強調
It is knowledge and care that the teachers give us.
九、習語或固定搭配：
1、That's it. 原因就是這樣
That's it. I can’t put my heart into my study when you are so noisy.
原因就是這樣，你這麼吵，我無法全神貫注學習。
2、make it 兩種漢語意思
1）約定在…
Let’s make it half past ten.
咱們定在十點半吧。
2）成功做到
Don’t worry. Keep trying and you are sure to make it.
別著急，堅持下去，你一定會成功的。
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，我會按照你說的做的。
4、Take it easy. 別著急，慢慢來It's my turn
it九大用法是中考中的高頻考點，同時形式主語的使用也是作文寫作中的一個利器，一定要認真學習掌握喲。
原創，版權所有。