It的基本用法
1.it用作人称代词，代替事物，区别one。
That vase is valuable. It's more than 200 years old.
那个花瓶很珍贵，它有200多年的历史。
Tom’s mother kept telling him that he should work harder, but it didn’t help.
2.it用以代替指示代词this, that.
1)--- What's this? --- It's a pen. —这是什么？—是一支钢笔。
2）--- Whose book is that? --- It's Mike's. —那是谁的书？—是迈克的。
3.指示代词it，常用以指人。
1）Go and see who it is. 去看看是谁。
2）--- Who is making such a noise? —是谁发出这样的吵闹声？
--- It must be the children. —一定是孩子们。
4.当说话者不清楚或无必要知道说话对象的性别时，也可用it来表示。
1）It's a lovely baby. Is it a boy or a girl?
宝宝真可爱，是男孩还是女孩？
2)—Who’s there? --It’s me. Who else could it be?
由于对方不知道自己的性别，因此用it回答who的提问。
5.it可用来指代团体。
The committee has met and it has rejected the proposal.
委员会已开过会，拒绝了这项建议。
6. It常用来表示天气、气候、温度、时间、地点、距离等意义的句子中。
1）It is half past three now by my watch. 我的手表现在是三点半钟。
2）It is six miles to the nearest hospital from here.
这里离最近的医院也有六英里。
3）It was very cold; it snowed and grew dark.
天气很冷；下着雪，渐渐地变黑了。
7.it也常用来表示一般的笼统的情况。
How is it going with you?你近况如何？
8.it也常用于下列结构：
1）It looks as if the college is very small. 看起来这个学院很小。
2）It seems as though our plan will be perfect. 似乎我们的计划很完善。
3）It's my turn. 该轮到我了。
9. it也常用于某些习惯用语中作宾语，各个习惯用语有具体意义，但it并无具体意义。
Forget it不必在意，算了make it +时间把时间定在某时
take it easy 别着急，慢慢来take it that… 认为
come to it确保put it that.. 表达\写到\说到
see to it that 注意使……务必使……
1)—Could we see each other at 3 o’clock this afternoon?
--Sorry, Let’s make it another time.(咱们另约时间吧)
2）Please see to it that you get here on time tomorrow morning.
请务必明天早上准时到这。
10. it用作形式主语
1）It is difficult to translate this article. 翻译这篇文章很难。
2）What time would it be most convenient for me to call again?
什么时候我再给你打电话最合适？
3）It is no use going there so early. 这么早去那里没有用。
4）It has been a great honor your coming to visit me.
你的来访是我很大的荣幸。
5）It is strange that he did not come at all. 真奇怪，他竟还没来。
6）It seems that John is not coming after all. 似乎约翰终竟不来。
7）It happened that John was the only witness. 碰巧约翰是唯一的证人。
11. 用作形式宾语
(6123结构：6是指用于这个结构的6个常用的及物动词think,find,make,feel,believe,consider;1指形式宾语it；2指作宾语的名词和形容词；3是指作真正宾语的三种形式：动词不定式短语、动名词短语、that引导的宾语从)
1）I found it difficult to explain to him what happened.
我觉得向他解释清发生了什么事很困难。
2）He thought it no use going over the subject again.
他认为再讨论这个问题没有用了。
3）They kept it quiet that he was dead. 他们对他的死保密。
4）We must make it clear to the public that something should be done to stop pollution.
我们必须使公众明白应该采取措施制止污染。
12. 在英语中，有些动词（短语）不能直接跟宾语从句，须先接形式宾语it作形式宾语，然
后再把真正的宾语置后。常用的动词有appreciate“感激”，dislike“不喜欢”，hate “恨”，like“喜欢”，love“爱”，enjoy，prefer, take，depend on “依靠” ask for(要求)，insist on（坚持），see to（负责，确保）take …for granted（认为…理所当然）等
1) I hate it when people talk with their mouths full. 我讨厌人们满嘴食物讲话。
2) I would appreciate it if you could come to my birthday party.
3) She’ll answer for it that he passes the exam. 她将负责他通过考试这件事。
4) Will you see to it that the luggage is brought back as soon as possible?
你能确保把行李尽快带回来吗？
