高中英语it用法归纳：虚词it与指代

　　一、虚词it 虚义it指用作没有具体语义的主语，如表示时间、天气、距离、温度、环境等概念的用法。

　　It is cooler in Tianjin than in Beijing.

　　It is only about half an hour's ride from here to my home.

　　It’s three o’clock now.

　　It looks as if the college is very small.

　　It is very guiet at the moment.

　　二、指代

　　it的基本用法是用来指代上文所提到的事物,同时也可以用以代替指示代词this,that.

　　1.My dictionary is missing, I can’t find it anyway.

　　2.Tom has failed in the exam, have you heard about

　　it?

　　3.- What’s this?

　　-- it’s a computer.

　　4.- Whose bicycle is that?

　　-- it’s hers.

　　it, one, 用于指代用法时的区别:

　　it代替上文提及的原物(复数用they)；one指代上文提及的、泛指的可数名词单数（复数ones）

　　Do you want the watch?

　　Yes, I want it.

　　Do you want a watch?

　　Yes, I want one.

　　What is a panda like?

　　I’ ve never seen one, so I dont’ know what it is like.

　　指代不明身份或性别的人也用it ,有时可以用来指婴儿，有时还可以指引起某种情况的事物。

　　1.A:---Who is making such a noise?

　　B:---It must be the children.

　　2.It’s the wind shaking the window .

　　3.Look that lovely baby in the cradle! Oh, dear. It is crying.

　　4.A：Who's it (knocking at the door)?

　　B: It's me.