㈠ 1.it 作人称代词1.1.it 的最基本用法是作人称代词，主要指刚提到的事物，以避免重复 :Ningbo is a beautiful city, isn’t it?1.2. 也可以指动物或婴儿 ( 未知性别的婴儿或孩子 ):Is this your dog ？ No, it isn’t.1.3. 也可指抽象事物 :It was a great surprise to me when he did a thing like that ．2. 非人称代词 itit 有时并不指具体的东西，而泛指天气、时间、环境等，称为非人称的 it ：2.1. 指天气：It is a lovely day, isn’t it?It is a bit windy. 2.2. 指时间 :It was nearly midnight when she came back.2.3. 指环境 :It was very quiet in the café.2.4. 指距离：It is half an hour’s walk to the city centre. 3.it 的其他用法3.1. 表示谁在做某事的句子：Who is it? ---It’s me.Her face lighted when she saw who it was. 3.2. 用来泛泛的指某件事：So you are going to be married this time ？ When is it ？It doesn’t matter.It is a shame, isn’t it? ㈡ .it 的重要句型1. It is + 被强调部分 + that ... 该句型是强调句型。将被强调的部分放在前面，其它部分置于 that 之后，被强调部分可以是主语，宾语，表语或状语，强调的主语如果是人， that 可以由 who 换用。如果把这种句型结构划掉后，应该是一个完整无缺的句子；这也是判断强调句型与其它从句的方法。 It was about 600 years ago that the first clock with a face and an hour hand was made. It was they that (who ) cleaned the classroom yesterday. It was in the street that I met her father. 2. It is not until + 被强调部分 + that ... 该句型也是强调句型。主要用于强凋时间状语，译成汉语＂直到．．．才．．．＂，可以说是 not ... until ... 的强调形式。 It was not until she took off her dark glasses that I realized she was a famous film star. = Not until she took off her dark glasses did I realize she was a famous film star. = I didn’t realize she was a famous film star until she took off her dark glasses. 3. It is clear ( obvious ，...
