三分钟语法课（25）：副词从句的简化（下）
【回顾】
上一节我们学习的内容是副词从句三种特别的简化方式： 1. 简化后保留连词，变成：连词+分词；
2. 主从句主语不一致，保留从句主语：主语+分词。 3. 简化为介词词组，即：介词+动名词或名词。
我们留了四个句子给大家：
第一句：Although they were warned, they proceeded carefully. 如果我们简化为：Warned, they proceeded carefully. 那么它就可能被理解为：
After they were warned, they proceeded carefully.（得到警告后，他们谨慎前行。） 或者：
Because they were warned, they proceeded carefully. （因为已经得到警告，他们谨慎前行。） 因此，为确保句子原意，保留连词although——
Although warned, they proceeded carefully.（虽然得到警告，他们还是谨慎前行。）
第二句：After he wrote the letter, he put it to mail.
简化为介词+动名词：After writing the letter, he put it to mail. 同样，如果不保留after，这句就成了：
Writing the letter, he put it to mail.（一边写着信，他一边拿去邮寄。） ——这怎么可能呢？
我们还学习了一种简化式：即介词词组。比较常见的有On/Upon，after，before，because of。这种又包括三种情况：介词+名词；介词+动名词；介词+动名词的被动式。例如：
第三句：Before it was redecorated, the house was in bad shape.
简化为介词+动名词被动式：Before being redecorated, the house was in bad shape. 或者简化为介词词组：Before redecoration, the house was in bad shape.
第四句：The construction work was delayed because it had been raining. 只能简化为介词词组：The construction work was delayed because of rain.
我们接下来要学习的内容，跟BE、以及非谓语动词的完成式有关。
【概念】
一、副词从句简化为：Being……
BE本身是谓语动词、而非助动词，则不可省略
例1. As I am a student, I can't afford to get married. 简化：Being a student, I can't afford to get married. 或者：As a student, I can't afford to get married.
（作为一个学生，我还不能结婚。）
这里am显然表示“是、作为”，不可省。所以，要么简化成Being、要么留下连词As。
例2. Although he was a doctor by training, Asimov became a writer.
简化：Being a doctor by training, Asimov became a writer. 或者：Although a doctor by training, Asimov became a writer.
（虽然接受的是做医生的训练，但阿西莫夫后来成了作家。）
同样的，was表示“是、作为”，不可省。要么简化成Being、要么留下连词although。
二、副词从句简化为：Having + v-ed……
简化副词从句还得注意：如何体现出原来的时态？比如前面的第二句： After he wrote the letter, he put it to mail. 可以简化成“介词+动名词”：
After writing the letter, he put it to mail. （写完信后，他把它寄掉了。）
那么，如果一定要用分词简化、还要体现“已经写好了”，这就用到了分词完成式： Having written the letter, he put it to mail.
又比如这个句子：Having realized that I could use a kite to attract lightning, I decided to do an experiment. 根据having realized这个完成式，我们能看出，他想表达的是“在意识到……之后”，即After I realized……。
三、副词从句简化为：Having + been + v-ed 前面第一句，如果是：
Because they had been warned, they proceeded carefully. （因为受到警告，他们谨慎前行） 我们把它简化为：
Having been warned, they proceeded carefully. 或：Warned, they proceeded carefully.
就会发现，这两种形式其实是一样的。也就是说，作为副词从句的简化式，having been + v-ed实际上和过去分词的功能是一样的。
【联系】
副词从句最常见的简化方式，是省略主语和BE动词。按照这个原则，当BE动词后是介词词组、形容词等，也是适用的。
例3. When you are under attack, you must take cover immediately. 简化：When under attack, you must take cover immediately.
（受到攻击时，要立刻寻找掩护。）
例4. While it is small in size, the company is very competitive. 简化：While small in size, the company is very competitive.
（这家公司規模虽小，但很有竞争力。）
还可以将从句改换成介词+名词的方式：
例5. Although he opposed it, the plan was carried out. 简化：Despite his opposition, the plan was carried out.
例6. When she arrived at the party, she found all the people gone.
简化：Upon her arrival at the party, she found all the people gone.
【小结】
今天的内容可以总结为：
1. 从句中BE本身表示“是、作为”，则简化成Being…的形式； 2. 为了表现时态——即此事已经发生，则用having + v-ed形式； 3. 分词的完成被动式，即having been + v-ed，等同于单个v-ed。 拓展部分，我们将分词简化原则应用到：
4. 从句是BE + 介词词组或形容词，也可以简化为“连词+介词词组/形容词”。
【思考】
到此为止，我们了解了非谓语动词词组的“来历”、以及各种变化形式。下面这些句子，代表了“副词从句简化”全部的规则。
1. Since I didn’t have enough money to go on vacation, I stayed home. 2. John will visit the market today as he has to buy a pair of new shoes.
3. My sister is studying honours physics, since she is determined to become an astronaut. 4. Since it was so hot, we didn’t go out today.
5. Whether it is insured or not, your house needs a fire alarm. 6. Although she earns a low salary, Wendy often goes traveling. 7. Suppose you are a volunteer, what can you do to help people? 8. They were full up because they had eaten so much grass. 9. She is confident than she was ever before.
10. Before he was in school, he used to be a naughty child.
[key]
1. Not having enough money to go on vacation, I stayed at home. 2. John will visit the market today to buy a pair of new shoes. 3. My sister is studying honours physics, determined to become an astronaut. 4. It being so hot, we didn’t go out today.
5. Whether insured or not, your house needs a fire alarm. 6. Despite her/the low salary, Wendy often goes traveling. 7. Being a volunteer, what can you do to help people? 8. Having eaten so much grass, they were full up. 9. She is confident than ever before.
10. Before being in school, he used to be a naughty child.
三分钟语法课(25)副词从句简化(下)
