It的用法
一、Tell the functions for “it” in each sentence:
1、---What’s the weather together?
---It is fine.
2. It is hard to communicate with him.
3. I find it hard to communicate with him.
4. It is Li that who cleaned the classroom.
5. It is a book.
二、It 用法归纳
1，指代it （1）.用作人称代词：指代物、整个句子
（2）用作非人称代词
2，形式it：（1）作形式主语（2）作形式宾语
3，强调it
4，特殊句型
5.在答语中指代this/that：
1).---Whose book is that? ---It’s mine.
三、特别注意：it,one和that作替代词的用法及区别
1.it代替前面提到的同一事物,该事物既可以是可数名词也可以是不可数名词。
(特指，指代单数，指代物，同名同物)
Can I borrow your pen?—Sorry，I’m using it.
2.one代替前面提到的同类事物中的一个。
该事物只能是可数名词,前面可以有冠词,也可以被this、that或形容词修饰,其后也可以有定语。
（泛指，指代可数名词，指代人或物，同名异物）
I have a bike. Do you have one?
Eg:
(1).I bought a dictionary three years ago and I am still using______ now.
(2) I bought a dictionary three years ago but I am going to buy a new _______soon.
(3).that代替前面提到的同类事物中特指的一个。
该事物既可以是可数名词也可以是不可数名词,必须要有后置定语,但不可以有前置修饰语。
（特指，指代单数或不可数，指代物，后面有定语）
The coffee produced in Brazil is more famous than __________in Mexico.
四：形式主语、宾语、强调句及其他
1、形式主语It
It is important to give the money back to him on time. 不定式
It is no use arguing with such a person. 动名词
It is said that he was the No.1 in the competition. 主语从句
it作句子的形式主语, 后面被指代的主语包括：
不定式
动名词
主语从句
It替代作主语的动名词
It‘s no good/use doing…
It's(well)worth doing…
例It's no use crying over spilt milk.
形式主语中的虚拟语气
1.It is important ( necessary，strange，natural...) that ...
It is important that we (should) have enough rice.
2.It's surprising that…(should)………竟然……
例It's surpring that you should apologize to her without any reason.
3.It is suggested ( ordered /demanded/insisted/commanded... ) that ...
that后的从句要用虚拟语气（should + 动词原形），should 可以省；常译为“据建议；有命令．．．）
4.It is suggested that the meeting ( should ) be put off.
5.It is a pity ( a shame ... ) that ...
that后的从句一般用虚拟语气（should + 动词原形），常译为“竟然”。
没有这种意义时，则不用虚拟语气。
例如；It is a pity that such a thing ( should ) happen in your class.
6、It is adj ( for sb. ) to do sth.
important，necessary，natural ，impossible ，unusual ，rare ，normal ，easy ，hard ，difficult ，dangerous ，pleasant ，likely,right,wrong,,,clear,
obvious,certain,suitable,proper,useful,等、
7. It is adj ( of sb. ) to do sth.
good （好心的），nice（有教养的），polite，kind ，brave ，careless，honest ，modest ，considerate,naughty ，wise ，clever ，thoughtful,careful,crazy，bad ，lazy ，rude ，cruel ，foolish ，silly ，stupid ，.等。
这个句型可以改写为：sb. is adj to do sth. 。
It is kind of you to say so.
= You are kind to say so.
2、形式宾语it
I think it important to give the money back to him on time.
I find it no use arguing with such a person.
I knew it when he left without saying a word.
it 作形式宾语时，句子的真正宾语是：
不定式
动名词
宾语从句
固定句型：
1、owe it to sb.that…把…归功于…
2、see to it that:务必.../负责...
3、I like (enjoy, hate，dislike…) it when….: 我喜欢/讨厌...
4、I would appreciate it if…：如果...我将不胜感激
5、keep it in mind that…把…记在心里
6、I like (enjoy, hate…) it when….
7、I would appreciate it if…
3、强调句it
It is/was+被强调部分+that(who)…
用来强调谓语动词以外的任何句子成分。
当
被强调部分是人时也可以用who。
4、其他含有it的句式
It is time ( about time ，high time ) that ...
例如：It is the first ( second ... ) time that ...
It is the first time I have been here.
= This is the first time I have been here
It is .... since ...。
since 引导的从句通常是一般过去时态，而且是瞬间动词。
“做某事已经多久了”
例如：It is ( has been ) 5 years since his father died.
It is…since+延续性动词的过去式“不做某事已经多久了”
例。
It‘s10years since he had breakfast
It is ... when ...。
when 引导时间状语从句，主句中的it 指时间，表语由具体的时间充当，常译为＂当．．．的时候，是．．．＂
例如：It was 5 o’clock when he came here.
It be ... before ...
when从句中常是将来一般时或过去时两种时态．主句中的it 指时间，表语多是long，not long ，3 days ，2 weeks 等表示时间段的词或短语，常译为＂．．．后．．．＂。
例如：It was 3 days before he went to Beijing.
It will be not long before he finishes his job.。