通过结构来判断是否为强调句。英语常用的强调结构是"It is (was)+被强调部分(主语、宾语或状语)+who (that)..."。一般说来,被强调部分指人时,用who;指事物时用that,但that也可以指人。在美国英语中指事物时常用which来代替that。强调句(The Emphatic Pattern)是一种修辞通过各种方式对句子中的某个部分进行强调，从而起到修辞的作用。常用句型1. 陈述句的强调句型It is/ was + 被强调部分（通常是主语、宾语或状语）+ that/ who（当强调主语且主语指人）+ 其他部分。例子 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 didn"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。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didDo 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
