句型11
　　It强调句型
　　强调句的基本构成：It is/was + 被强调的部分 + who(主要指人时)/that + 其余部分
　　[注意1]
　　这种结构可以强调句子的主语、宾语、状语(包括时间，地点，方式，原因等)，但是不能强调谓语动词(参考句型15)。
　　原句的谓语动词如果是现在或将来时态，用It is…that/who….;
　　原句的谓语动词如果是过去时态，用It was…that/who….;
　　强调时间、地点、原因或方式时不要用when, where或how, 必须用that。
　　[例句1]
　　I saw him in the street yesterday afternoon.
　　→It was I who saw him in the street yesterday afternoon.(强调主语)
　　→It was in the street that I saw him yesterday afternoon.(强调地点状语)
　　→It was yesterday afternoon that I saw him in the street.(强调时间状语)
　　→It was him that/who I saw in the street yesterday afternoon.(强调宾语)
　　[例句2]
　　He didn't go to bed until his mother came back.
　　→It was not until his mother came back that he went to bed.
　　He didn't do his homework until his father came back from work.
　　→It wasn't until his father came back from work that he did his homework.
　　[例句3]
　　Only when you nearly lose someone do you fully realize how much you value him.
　　→It is only when you nearly lose someone that you fully realize how much you value him.
　　只有你快要失去某个人时，你才意识到你是多么尊重他。
　　[例句4]
　　I was late again because the traffic was very heavy during the rush hour.
　　→It was because the traffic was very heavy during the rush hour that I was late again.
　　(强调句中只能强调由because引导的原因状语从句，because不能换成since, as, for, now that等)
　　[注意2]强调句的疑问结构
　　一般疑问句 Is / Was it +被强调部分 +who / that …?
　　特殊疑问句 特殊疑问词+is /was +it +who / that…?
　　What is/was it that…? Who is/was it that…? When is/was it that…?
　　Where is/was it that…? Why is/was it that…? How is/was it that…?
　　[例句1]
　　I saw him in the street yesterday afternoon.
　　→When was it that you saw him in the street?
　　→Who was it that you saw in the street yesterday afternoon?
　　→Where was it that you saw him yesterday afternoon?
　　[例句2]
　　I don't know when he will come back.
　　→I don't know when it is that he will come back.(宾语从句疑问词后用陈述句语序)
　　-How was it that you got in touch with Mr. Smith? 你是怎么和Smith先生联系上的?
　　-Trough a friend of mine. 通过一个朋友。

　　句型12
　　(1)、祈使句(表条件)+ or/or else/ otherwise + 主句(表结果)… "否则…，要不然…"
　　(2)、祈使句(表条件)+ and +主句(表结果)
　　[例句]
　　Hurry up, or you'll be late for class.
　　Please call me up before you come, otherwise/or else/or we might be out.
　　你来之前打个电话，否则，我们也许会出去。
　　Think it over and you will find the answer.
　　Give him an inch and he will take a mile. 得寸进尺。
　　Work hard and you will make progress every day. 好好学习，天天向上。

　　句型13
　　…until…."直到……时候";not…until…"直到……才……"
　　[例句]
　　You are to stay until/till your mother comes back. 你得等到你妈妈回来。
　　The meeting was put off until ten o'clock. 会议推迟到十点钟。
　　The villagers didn't realize how serious the pollution was until all the fish died in the river.
　　→Not until all the fish died in the river did the villagers realize how serious the pollution was.(倒装句)
　　等到湖里的鱼全死光了，村民们才意识到污染是多么严重。
　　He didn't go to bed until his mother came back.
　　→It was not until his mother came back that he went to bed.(强调句)
　　Not until he failed in the exam did he realize that he had wasted much time playing computer games.
　　Not until his son came back from school did he go to bed.