一、强调句型的功能:
强调句型的基本结构：
It is/ was 被强调部分＋that/ who 其他部分
本句型可以对句子中的主语，宾语，补语，状语等句子成分进行强调。如果强调人，可用who或that;如果强调的是其他，一律用that。
1. 强调主语
被强调的主语是人时，可用it is/was ... that/ who ...，但如果被强调的部分既包括人又包括物，只能用that。
It is Wei Fang who has broken the record. 是魏方打破了纪录。
2. 强调宾语
It was me that she helped yesterday. 昨天她帮助的人是我。
3. 强调宾语补足语
It was chairman of the meeting that we elected him. 我们选他是做会议的主席。
4. 强调状语
英语中的状语种类很多,一般都可以用it is / was ... that ...来强调。
It was at the age of 5 that he left his hometown for Taiwan.
5.谓语动词的强调
A. It is/ was ... that ... 结构不能强调谓语，如果需要强调谓语时，用助动词do/ does或did
Do sit down. 务必请坐。
Do be careful when you cross the street. 过马路时，务必（千万）要小心啊！
B. 注意：
此种强调只用do/ does和did，没有别的形式；过去时用did，后面的谓语动词用原形。
二、强调句型的形式
1.陈述句的强调句型
It is/ was 被强调部分 that/ who（当强调主语且主语指人） 其他部分。
例 It was yesterday that he met Li Ping.
2.一般疑问句的强调句型
同上，只是把is/ was提到it前面。
例子 Was it yesterday that he met Li Ping?
3.特殊疑问句的强调句型
被强调部分（通常是疑问代词或疑问副词） is/ was it that/ who 其他部分？
例子 When and where was it that you were born?
4.not … until …句型的强调句
A. 句型为：It is/ was not until 被强调部分 that 其他部分
普通句：He ddid't go to bed until/ till his wife came back.
强调句：It was not until his wife came back that he went to bed.
B. 注意：
此句型只用until，不用till。但如果不是强调句型，till, until可通用；因为句型中It is/ was not ... 已经是否定句了，that后面的从句要用肯定句，切勿再用否定句了。
三、使用强调句型应注意的问题：
1. 去掉强调结构It is (was) …that(who)…后，剩下的词仍能组成一个完整的句子。这是判断是不是强调句型的关键。试比较：
1）. It is strange that he didn’t come yesterday.
2）. It is you and Tom that didn’t come yesterday.
显然，句1去掉It is…that…后，句子结构不完整，是主语从句；句2去掉It is… that …后，句子变为you and Tom didn’t comeyesterday. 仍是一个表意完整的句子，这是一个强调句。
2. 如果强调时间、地点、原因或方式状语时，不可用when,where,why或how，而仍用that。
试比较：It was because of the accident why he was late.(误),
It was because of the accident that he was late.(正)。
3. 在强调句型中，that或who后面的谓语动词的形式仍然取决于原句中的主语；
be的变化只有is和was两种形式，如果要表示现在时将来时的其它各种形式时，
就用It is…, 表达过去时的各种形式时，用It was….一般要与谓语动词的时态一致。
1）. It is I who/ that am an English teacher.
2）. It is the boy who/ that speaks English best in the class.
3）. It was on Sunday that he gave George this ticket.
4）. It is the little girl who/that has broken the glass.
