it isthat强调句型结构

强调句的基本结构：it is(was)+被强调的成分+that+句子剩余部分。

注意1：该结构可以对所有成分（谓语除外）进行强调。

I saw him yesterday.

对主语进行强调：It was I who/that saw him yesterday.

对宾语进行强调：It was him who/that I saw yesterday.

对状语进行强调：It was yesterday that I saw him.

对谓语部分强调: I did see him yesterday..

注意2：is/was只能是单数，不能写成are。

It was the beautiful birds that stunned me.

注意3：当所强调的是人时，that可以替换为who。

It is my sister who always helps me out.

注意4：在informal场合，that/who可以省略。

A: You've met my mother, haven't you?

B: No, it was your sister (that) I met!

注意5：强调句去掉it is…that/who…之后剩下的是一个完整的句子。

It was the government that guarantee the running of the country.

注意6：Not until句型的强调。

It was not until his wife left that he came back.

注意7：it is可以加上情态动词。

It might be in this room that he met her.

It might have been John that bought a present for Mary yesterday.

It must have been Bill who phoned yesterday.