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.
句型14
unless… "除非，如果不……"(=if…not)
[例句]
I shall go tomorrow unless it rains. 如果不下雨，我明天去。
-Shall Tom go and play football?
-Not unless he has finished his homework. 除非他完成作业，否则不能出去。
I won't go unless he comes to invite me himself.
除非他本人来邀请我，不然我是不会去的。
I won't attend his birthday party unless invited (=unless I am invited). 除非被邀请，否则我不
去参加的生日晚会。
句型15
when引导的从句
when除了用来引导主语从句、宾语从句、时间状语从句、表语从句和定语从句，还有一种用法值得关注，那就是when引导并列分句，意思是"这时突然；就在那时"，强调另一个动作的突然发生。常用于以下句型中：（1）、主语 + be doing… when…意思是"正在做某事这时……"；（2）、主语 + be about to do…when…；（3）、主语+be on the point of (doing) …when…意思是"正要去做某事这时……"
[例句]
One day Chuck was on a flight across the Pacific Ocean when suddenly his plane crashed. 有一天，Chuck正在太平洋上飞行，这时他的飞机突然爆炸了。
I don't know when he will arrive. 我不晓得他什么时候到达。
I thought of the happy days when I was in Beijing. 我想起了在北京时的那段快乐日子。
I believe the time will soon come when there will be no weapons in the world. 我相信世界上没有武器的日子不久就会到来。
I was walking along the river when I heard a drowning boy cry for help. 我正在河边行走，这时我突然听到一个落水男孩求救。
I was about to leave when it began to rain. 我刚要离开，这时下雨了。
I had just finished my exam paper when the bell rang, announcing the class was over. 我刚做完作业，下课铃响了。
I thought of the happy days when I was in France. 我想到了在法国时那段快乐日子。
I believe the time will soon come when there will be no weapons in the world. 我相信世界上没有武器的日子不久就会来临。
[比较]
I was walking along the street when I caught sight of a tailor's shop. 我正在街上走，这时我看见一家裁缝店。
I was walking along the streets. Just at the moment I caught sight of a tailor's shop. 我在街上走。就在那时我看见一家裁缝店。
句型16
while引导的从句
while除了有"当/在……时候"的意思外（注意：引导的句子谓语动词只能是延续性动词！），另外的两层意思也是考查的重点：（1）while = although "尽管"、"虽然"，引导让步状语从句；（2）while的意思是"然而；可是"，常用来表达对比关系。
[例句]
While I admit that the problem is difficult, I don't think that they can't be solved.
尽管我承认这个问题很难，但是我并不认为无法解决。
While I admit his good points, I can see his shortcomings.
虽然我承认他的优点，我也能看出他的缺点。
While I was angry with her, I didn't lose my temper.
虽然我很生气，但我当时没有对她发脾气。
While I understand your viewpoint, I don't agree with you. 虽然我了解你的见解， 我还是不能同意（你）。
I earn only 120 dollars a week, while she earns 180 dollars. 我一星期只赚120美元，她却赚180美元。
句型17
where…（地点从句）
[注意]where引导地点从句时，可以引导定语从句或是逻辑地点状语从句。当它在定语从句中作地点状语，指代地点时，这时可以用in which, on which, at which, to which, from which等结构代替。但是它引导逻辑地点状语从句时，没有这样用法。
[例句]
You should put the book where it was. 把书放回原处。
Persistent people begin their success where others end in failure.
不屈不挠者从他人失败的地方获取成功。
Where there is a will, there is a way. 有志者，事竟成。
Where men are greedy, there is never peace. 人类贪欲不止，世界和平无望。
Go where you should, keep on studying. 无论你到哪里，你都应该继续学习。
That is the building where my father works. 那是我父亲工作的大楼。
Yesterday I went to the department store, where I met my teacher. 昨天我去百货公司，就在那儿遇见了我的老师。
That's where a change is needed. 那就是需要变更的地方。
We could see the runners very well from where we stood. 从我们所站的地方能很清楚地看到赛跑的选手。
You should let your children play where you can see them. 你应该让小孩在你的视线所及的地方玩耍。
Potatoes can be grown in places where it is too cold to grow rice.=Potatoes can be grown in places where it is too cold to grow rice.（本句where引导定语从句）
有些地方太冷不能种水稻，但可以种马铃薯。
[请比较下面的句子结构的不同]
Potatoes can be grown where it is too cold to grow rice.（本句where引导地点状语从句）
句型18
what引导的从句
what在英语中非常活跃,它可以用来引导主语从句、宾语从句、表语从句，但是不用来引导定语从句。在句子里可以充当主语、宾语、表语、定语，既可以指人，也可以指物。
[例句]
What is the population of the world? 世界的人口有多少？
What did you pay for this picture? 这幅画你付了多少钱？
What is most important in life isn't money. 人生最重要的并非是金钱。
Will you show me what you bought? 可以把你所买的东西给我看一下吗？
Mary is no longer what she was ten years ago. Mary已经不是10年前的她了。
句型19
as引导的非限制性定语从句
在as引导的非限制性定语从句中，连接代词as在句子中可以作主语、宾语或表语等，可以指人或物。其在定语从句中的位置比较灵活，即可以在句子前面，在句子中间或句子末尾。常用的结构有：as we all know; as is well known to…; as is often the case; as is said/mentioned above; as has been said before; as I told you before; as is evident; as often happens; as can be seen; as is/was expected; as we expect; as I can remember等。
[注意1]as通常只指整个句子的内容，不表示部分内容。
[注意2]as引导的非限制性定语从句通常指"事先可以预料到的""料想到的"，表达"好"的方面。
[注意3]as引导限制性定语从句时，常构成the same…as…; such…as…; so/as …as…等结构。在从句中既可以指人、物，也可以指整个句子。
[例句]
This is also part of your work, as I told you before. 我曾告诉过你，这也是你工作的一部分。
The man was a teacher, as was evident from his way of speaking. 从那人说话的样子可明显看出，他是个老师。
Such ideas as he hits on are worthless. 像他那样偶然想起的主意是无用的。
It's the same story as I heard from her yesterday. 这故事跟我从她那儿听到的相同。
He will marry as pretty a girl as he can find. 他要尽可能找漂亮的女孩结婚。
Such people as have made great contributions to the world should be greatly respected.
那些对世界做出巨大贡献的人们应该受到极大的尊重。
句型20
which引导的非限制性定语从句（也引导限制性定语从句）
which引导的非限制性定语从句既可以指整个句子内容，也可以指句子的部分内容（如单词或词组等），在句子中可以作主语、宾语（动词或介词的）、定语等。注意它在句子中的位置：只能放在主句后，不能放在主句前。表达的内容是"不好的"、"事先没有预料到的"等时，常用which，只指物。
[例句]
Yellowstone National Park, which is in Wyoming, is one of the most beautiful national parks in the world. 黄石国家公园位于怀俄明州，是世界上最美丽的国家公园之一。
The clock, which my grandfather bought, is still in good order. 这时钟是我祖父买的，现在还走时很准。
The picture, for which he paid an enormous amount of money, was a forgery.
那幅画他花了一大笔钱购买，却是幅赝品。
She changed her mind again, which made us all angry. 她又改变了主意，这使我们大家都生气了。
I lived three years in Paris, during which time I learned French. 我在巴黎住了三年，在那期间我学了法语。
The weather turned out to be very good, which was more than we could expect. 天气结果转晴，
这是我们没有预料到的。
