职称英语理工类语法词汇常见考点：it引导从句

　　为了突出句子的某个部分，我们可以使用强调句式。　　常见的强调句结构是it 引导的句子。　　It is 被强调部分+ that 被强调部分+ that + 句子其他部分。

　　此结构强调的成分仅限于主语，宾语和状语。

　　It is from the sun that we get light and heat.

　　It was not until I had read your letter that I understood the true state of affairs.

　　使用此句型时, 应注意以下几点。

　　 一般情况用It isthat如:

　　He read three books in the library yesterday.

　　我们分别可以强调主语、宾语、地点状语和时间状语。如:

　　It was he whoread three books in the library yesterday.

　　It was three books that he read in the library yesterday.

　　It was in the library that he read three books yesterday.

　　 当被强调部分指人时, 可用that, 也可用who; 指物时, 只用that, 如:

　　It was Tom whoI met last week.

　　It is a new boke that his brother wants to buy.

　　 强调状语时, 只用that, 不用when、where. 如:

　　It is at 5 oclock that the train will arrive.

　　 被强调的部分是主语时, 注意句子的谓语动词和被强调的主语保持一致。如:

　　It is he who is late. 　It is they that were late.

　　 一般疑问句的强调句为Is it + that? 特殊疑问句为: 特殊疑问词+ is +that?结构。如:

　　Was it ten years ago that his father died?他的父亲是十年前去世的吗?

　　When is it that you will set off?你到底什么时候出发?

　　 notuntil句型的强调结构为It is not untilthat应注意把否定词not转移到until前面。如:

　　I didnt go home until rain stopped. 直到雨停了我才回家。

　　强调句为: It was not until rain stopped that I went home.

　　I didnt know the news until yesterday. 直到昨天我才知道那个消息。

　　强调句为: It was not until yesterday that I knew the news.

　　原句: 　My father did the experiment in the lab yesterday evening.

　　强调主语: It was my father who did the experiment in the lab yesterday evening.

　　强调宾语: It was the experiment that my father did in the lab yesterday evening.

　　强调时间: It was yesterday evening that my father did the experiment in the lab.

　　强调地点: It was in the lab that my father did the experiment yesterday evening.

　　C.倒装句：

　　英语中主语在前谓语在后的语序称为自然语序。由于语法、修辞的需要谓语置于主语之前，称为全部倒装; 助动词、情态动词等移到主语之前而主要动词仍然在主语之后的，称作半倒装。 全部倒装和半倒装的句子统称倒装句。