it用法大归纳

1. 有时可用来指人，但主要限于指性别不明的婴儿或指身份不明的人。如：

They got a baby and it was very lovely. 他们生了个孩子，很可爱。

Someone is knocking at the door. It must be Jim. 有人在敲门，一定是吉姆。

下面这样的句子也用 it 指人。如：

A：Who is it? 是谁呀?

B：It’s me, Mary. 是我玛丽呀。

2. 用于强调句型：It is (was) …that (who) …。如：

He bought a shirt at this shop yesterday. 昨天他在这家商店买了一件衬衫。

下面4句分别对上句主语、宾语、地点状语、时间状语的强调：

It was he who bought a shirt at this shop yesterday.

It was a shirt that he bought at this shop yesterday.

It was at this shop that he bought a shirt yesterday.

It was yesterday that he bought a shirt at this shop.

3. 用作形式主语或形式宾语：

(1) 当不定式、动名词、从句等结构用作主语时，为了避免“头重脚轻”，往往用it作形式主语，而把真正的主语放在句子末尾。如：

It’s no use talking about it now. 现在谈这事没有用。

It’s important to know your own limitations. 知道自己的局限性是重要的。

It is said that thirteen is an unlucky number. 据说13是一个不吉利的数字。

(2) 当不定式、动名词、从句等结构用作宾语时，若其后跟有宾语补足语，则往往使用 it作形式宾语，而把真正主语放在句末。如：

I find it easy enough to get on with Pam. 我觉得与帕姆相处很容易。

I took it for granted that you would stay with us. 我肯定你会住在我们这里的。

4. 某些及物动词（如 like, love, enjoy, prefer, hate, appreciate等）之后若没有出现宾语，而直接跟 if/when 引导的状语从句，要在从句前使用代词 it。如：

I like [love] it when you sing. 我喜欢听你唱歌。

I dislike it when you whistle. 我不爱听你吹口哨。

I hate it when Jane cuts up in class. 我讨厌简课堂上插嘴。

I’d appreciate it if you could drop in tonight. 你今晚来一趟我会很感激。

I should prefer it if you did not go there alone. 我倒希望你不要一个人去那里。

5. 在某些特殊表达中的使用。如：

It seems that John dislikes his boss. 约翰似乎不喜欢他的老板。

It happened that the harvest was bad that year. 恰好那年收成不好。

It doesn’t matter if you can’t find her. 如果你找不到她，也没有关系。