语法讲解：强调句

语法讲解：强调句
   一、强调句句型
    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。
    e.g. 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。
    e.g. 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？
    e.g. When and where was it that you were born？
    4. 强调句例句：针对I met Li Ming at the railway station yesterday.句子进行强调。
    强调主语：It was I that （who） met Li Ming at the railway station yesterday.
    强调宾语：It was Li Ming that I met at the railway station yesterday.
    强调地点状语：It was at the railway station that I met Li Ming yesterday.
    强调时间状语：It was yesterday that I met Li Ming at the railway station.
    5. 注意：构成强调句的it本身没有词义；强调句中的连接词一般只用that， who，即使在强调时间状语和地点状语时也如此，that， who不可省略；强调句中的时态只用两种，一般现在时和一般过去时。原句谓语动词是一般过去时、过去完成时和过去进行时，用It was …… ，其余的时态用It is …… .
    二、not … until … 句型的强调句
    1. 句型为：It is/ was not until 被强调部分 that 其他部分
    e.g. 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.
    2. 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、谓语动词的强调
    1. 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.
    e.g. Do sit down. 务必请坐。
    He did write to you last week. 上周他确实给你写了信。
    Do be careful when you cross the street. 过马路时，务必（千万）要小心啊！
    2. 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。