it的概念:
it可用作人称代词、指示代词、先行词及引导词等。
it 的用法:
1.it可指天气、温度、时间、距离等 。
如:It is cold today, isnt it?
2.用作人称代词,代替前文提到过的事物。
如:The dog is not acold-blooded animals. It doesnt need to hibernate.
3.为避免重复,it可用来代替前面说过的短语或句子。
如:I tried to persuade my father to give up smoking, but found it impossible. (it=to persuade my father to give up smoking)
4.代替指示代词this,that。
如:—Whats this?
—Its an album.
—Whose new bike is that?
—Its Marys.
注:it与one,that的区别:
it=the(this, that)+名词,特指并且代替前面所提到的某特定事物。
如:Hes bought a new car, so he drives it everywhere to show ito ff.
one=a+名词,one指前面提到的同类事物中的不同的另一个。
如:He needs a computer, but he cant afford one.
that=the+名词,that指代的名词与前面的名词属于同一类,但不属同一个。
如:The population of China is larger than that of Japan. that指代population,但其后有一个of短语作定语,以区别于the population of China。
注:it与that的异同:
it指同一事物,that指同类但并不是同一事物。
如:I like the climate of Kunming more than that of Beijing.
The climate of Kunming is mild, and I like it.
5.It/This/That+be+the first(second, third...) time+that-clause 这个句型表示截止到说话时为止的某人的一种经历,关键是注意time前有序数词,主句是一般现在时is时,从句要用现在完成时;如果主句用一般过去时was时,则从句须相应地用过去完成时。
如:This is the first time(that) these Europeans have visited the Great Wall.
It was the fifth time(that) I had paid a friendly visit to America.
6.在一些相对固定的词组中,没有特殊含义,经常不翻译。
如:Hes never really made it as an actor. 作为演员,他从未获得过真正的成功。
It is my turn. 轮到我了。
强调句中的it:
可以用来改变句子结构,使句子的某一成分得到强调:
1)强调句的基本句型its/was+被强调成分+that/who+其他成分
原句:I told Jim the news in our office yesterday.
强调主语:It was I that/who told Jim the news in our office yesterday.
强调宾语:It was Jim that I told the news in our office yesterday.
或:It was the news that I told Jim in our office yesterday.
强调地点状语:It was in our office that I told Jim the news yesterday.
强调时间状语:It was yesterday that I told Jim the news in our office.
2)强调句的一般疑问句型Is/Was+it+所强调部分+that/who...?
如:Was it you that told Jim the news in your office yesterday?
3)强调句的特殊疑问句型疑问词+is/was+it+that/who...?
如:Who was it that told Jim the news in your office yesterday?
【注】强调句与主语从句虽然在形式上很相似,即都含有it is(was)...that。但,区别在于:强调句去掉it is(was)…that之后,句子结构仍然完整,而主语从句却不能这样。
如:(It is)our hope(that) the two sides will work towards peace.
解析:去掉It is…that之后,句子是不成立的。由此得出该句不是强调句,而是一个简单的主语从句,it是形式主语,从句是真正的主语。