1、强调句的构成:
It is/was +被强调的成分+ that +其它成分
2、关于“被强调成分”
⑴“被强调的成分”最常见的是句子的主语、宾语、状语，特殊情况下也可能是宾语补足语、表语等成分。如：
My father met with an old friend of his [in the street] [yesterday].
→ It was my father that/who met with an old friend of his in the street yesterday.（主语）
→ It was an old friend of his (that/whom) my father met with in the street yesterday.（宾语）
→ It was in the street that my father met with an old friend of his yesterday.（地点状语）
→ It was yesterday that my father met with an old friend of his in the street.（时间状语）
⑵“被强调的成分”通常不能是表语、谓语动词、though/although引导的让步状语从句或whereas引导的从属分句等。但是，如果当系动词不是be,且表语部分是名词性词组时，强调句也可以强调表语。如：
①The picture is wonderful.
→It is wonderful that the picture is. (×)
②He becomes head of the department now.
→It is head of the department that he becomes now. (√)
⑶“被强调的成分”是原因状语从句时，只能强调由because引导，而不能强调由since/as/why 等引导的原因状语从句。
It was because the water had risen that they could not cross the river. (√)
It was since they’ve obviously forgotten to phone me that I’ll have to phone them. (×)
⑷如果强调动作，“被强调的成分”也可以是动词的非谓语形式。如：It was meeting Peter that really started me off on this new line of work.
⑸ “被强调的成分”也可以是宾语补足语。
It is green that they painted the wall.
3、强调句中that的用法
⑴“被强调的成分”不论是时间状语还是地点状语，只能用that，而不能用when, where。
It was in Berlin that I first saw this film.
It was then that I recalled that I had left my wristwatch up in the bar.
⑵ “被强调的成分”如果是表示人的名词作主语或宾语时，常用who或whom代替that。
It was my father who met with an old friend of his in the street yesterday.
⑶“被强调的句子成分”如果是时间状语、地点状语、直接宾语或间接宾语时，that可省略。
It was in that bookstore (that) I came across that book.
It was a new dictionary (that) Father sent to me.
It was only yesterday (that) we first met.
It is not I (who) to blame.
4、强调句中的主谓一致
“被强调的成分”如果是人称代词作主语时，通常用主格代词，但在口语中也常常使用宾格形式，但要注意人称和数的一致。试比较：
I suppose it is I who am responsible.
I suppose it is me who is responsible.
5、强调句的常见句式变化
⑴ 强调句型的疑问结构
一般疑问句：Is/Was it that …?
特殊疑问句：特殊疑问词+is/was it that …?
Was it her that you were talking about?
Was it last year that you got the scholarship?
Where was it that you saw the man?
Who was it that you want to see?
How is it that your answer differs from his?
What is it that you want me to say?
⑵“被强调的成分”如果是状语，且主句又为否定句时，通常发生“否定的转移”。如：
①I did not see my mother again until last year.
→ It was not until last year that I saw my mother again.
②He did not feel happy until he saw her.
→ It was not until he saw her that he felt happy.
③I did not have an opportunity of seeing them again for several years.
→ It was not for several years that I had an opportunity of seeing them again.
④I did not do it for myself.
→ It was not for myself that I did it.
6、强调句和限制性定语从句的区别
⑴ 强调句的“黄金法则”：在强调句型中，任何情况下使用It和that都不会错。注意：使用了it和that的句子并不一定都是强调句。
⑵ 强调句中的that是个虚词，在句中不充当任何成分，无实在意义，仅起着标志性作用，有时可以省略。
定语从句中的that作用有三：
一是引导定语从句
二是指代先行词，表示人或物
三是代替先行词在从句中充当主语、宾语或状语等成分。充当宾语时常常可以省略。
⑶ 强调句的谓语动词一般只能是现在时或过去时的单数形式is和was，偶尔根据需要可采取复杂的形式。如：
It must have been his father that you saw just now.
It might be his father that you’re thinking of.
但定语从句的谓语动词则有时态、语态、语气等各种形式的变化。
⑷ 强调句的“判别方法”——强调句如果去掉了It is/was … that …还可以还原为一个正常语序的陈述句，而且保持句子的结构完整，意义不变。而定语从句去掉关系代词或关系副词后，则通常需要还原成为两个简单句。试比较：
It is the tool that is most needed.（强调）
→The tool is most needed.
This is the tool that is most needed.（定从）
→This is the tool. The tool is most needed.
加载中,请稍侯......
精彩评论