1. 在对句子中除述语动词以外的其他成分强调时，用it引导的强调句型来表示;被强调的成分可以是主语、宾语、子句或其他部分等。 it引导的强调句型??：it is (was)+被强调的成分+that(who, whom)+其余部分。句中的任何部分都可以被强调。如果被强调的部分是人，句型中的的that要用who或whom代替。

I remember it was he who took my car.

我想起来了是他拿了我的车。

who代替 that 强调主语 he。

It is the car that I am looking for!

这就是我正在找的小汽车。

强调宾语 the car。

It was my father who bought it for me.

是我爸爸昨天给我买的。

who代替 that 强调主语 my father。

It is I who am wrong.

是我错了。

who代替 that 强调主语 I。

It was yesterday that my father bought it.

是昨天我爸爸给我买的。

强调时间副词yesterday。

2. 如果用疑问句表示强调时，被强调部分需要用相应的疑问词如：who, whom, when, where等代替，句型??：疑问词+is(was) it+that+其他部分。

Where was it that you lost your car?

你在哪里丢的汽车?

3. it引导的强调句型可以强调子句。

It is while we are collecting these paper that my mother is preparing the supper.

当我们正在收拾这些纸时，我妈妈正在准备晚饭。

强调子句while we are collecting。

4. it在强调某人时，一般在正式场合用It is (was)+某人+who (whom)...;而在非正式场合用It is (was)+某人+that...。

It was he who is my good friend and good teacher.

他是我的好朋友和好老师。