概览

在理解了名词子句、副词子句和关系子句后，我们就有了足够的前置知识来理解最后一种高级技巧：减化子句。因为子句本身是一个独立的句子，所以很多情况下都会有与主句重复的元素。这种技巧就是旨在尽可能地减少句子中的重复元素，以获得更简洁有力的表达。

在对子句做减化时，除了原本在副词子句中表达逻辑的逻辑词、或是在名词子句中被当作连接词的疑问词，其他的连接词都可以省略。子句本身一般会省略主词和 be 动词，仅留下补语。而语气助动词和普通动词则会被处理为不定词片语或分词片语，也就是词类转化，从而以更精简的方式表达原本由一个子句传递的信息。

我们会分别讨论名词子句、副词子句和关系子句的减化方式。由于各种子句的来源及结构有许多种不同的情况，而语言最优先的事情永远是清晰的表达，所以我们需要分情况讨论所有处理方式的细节。

名词子句的减化

名词子句的减化可以分为以下三种情况：

1. 如果子句有 be 动词，那么需要省略 be 动词
2. 如果有语气助动词，那么将其减化为不定词片语 to V
3. 普通动词添加 -ing 词尾做词类变化

名词子句原本在主句中作为名词使用，而名词可以在句子中作为主词、受词、补语、同位格使用，属于不可删除的元素。所以减化后需要保持剩下部分的名词属性，如果不是，则需要做词类变化。总而言之，减化后的结果可能是动名词 Ving 或不定词片语 to V。

减化为动名词

如果子句中不存在语气助动词，那么通常的处理是将动词片语转化为动名词片语。而这个动名词片语将会承担减化前的名词子句原本承担的语法角色。所以我们需要从子句承担的角色的角度来分析减化。

子句主词如果与主句主词重复且无意义，那么通常会被省略。而当子句主词不重复且有意义时，就不可省略。

1. That you don’t have a cell-phone can save you a great deal of trouble.
   • Not having a cell-phone can save you a great deal of trouble.
   • 名词子句做主句主词，主词一致，可省略主词
2. The John was drunk is no excuse for the rude behavior.
   • John’s being drunk is no excuse for the rude behavior.
   • Being drunk is no excuse for John’s rude behavior.
   • 主词不一致，不可省略主词。动词片语变化为动名词
3. I dislike that I am kept waiting.
   • I dislike being kept waiting.
   • 名词子句做受词。我们并不经常使用原始句型，而是直接使用减化后的句子
4. The actor’s greatest achievement is that he has been nominated twice for the Oscar.
   • The actor’s greatest achievement is his having been nominated twice for the Oscar.
   • The actor’s greatest achievement is his two Oscar nominations.
   • 名词子句做补语。主词不一致不可省略
5. I am happy that you won the prize.
   • I am happy about the fact that you won the prize.
   • I am happy about you winning the prize.
   • I am happy about your winning the prize.
   • 名词子句做同位格。原始句子中经常省略子句前的同位名词，需要做句子结构分析才能与其他类型的子句区分开
   • 还原句子后，按常规做法减化

减化为不定词片语

如果子句中存在语气助动词，那么我们会将其减化为不定词片语。而不定词片语具有名词、形容词和副词的功能，语法角色较为灵活。所以我们需要从名词子句的来源来分析减化。

来自直述句

直述句通过添加无意义的从属连接词 that，构成名词子句。这种子句如果包含语气助动词，则可以将其减化为不定词片语。

1. It is important that one be honest.
   • It is important to be honest.
2. That John should go on such a mission is suicide.
   • For John to go on such a mission is suicide.
   • 无法省略的主词可以借助 for 来解决语法冲突

有一类借助形式主词 it 而强调的句型为：it is … that …。在减化主词时，如果原句为褒贬义，则借助介系词 of 处理减化后的句子。原因在于 of 表达了一件已经完成的事的所属关系，完成的事情才能被评价。

3. It is kind that you can say so.
   • It is kind of you to say so.
4. It didn’t take much time that Richard could learn skiing well.
   • It didn’t take much time for Richard to learn skiing well.
   • It didn’t take Richard much time to learn skiing well.
   • 可以借助授予动词 take 将减化后的句子重构为 S + V + O + O 的句型
5. I hope that I can get a raise next month.
   • I hope to get a raise next month.
   • 名词子句为受词
6. The best plan is that we should wait.
   • The best plan is to wait.
7. I expect that I will have finished this book by next weekend.
   • I expect to have finished this book by next weekend.
8. It is a pity that we should have missed the show.
   • It is a pity to have missed the show.

来自疑问句

对于 information questions，保留连接词，而 Yes/No questions，则改写为 whether to V 的形式。

1. I’ll tell you what you should do.
   • I’ll tell you what to do.
2. Whether yo go on or not will have to be decided soon.

副词子句减化

副词子句只有在主句主词和子句主词一致时才可以省略，否则会造成 Dangling Modifiers。副词子句的减化方式与名词子句类似，所以不再赘述。区别在于副词子句的连接词表达了子句间的逻辑关系，所以需要具体分析是否可以省略。

副词子句的减化结果可能为分词片语、不定词片语、名词、形容词和介系词片语。

减化为分词构句

减化后的分词构句在句首，具有表达原因的功能。放在句尾，则具有表达结果的功能。

1. Because he was itching to be playing again, the boy inserted more coins.

   • Itching to be playing again, the boy inserted more coins.

2. Two Vietnamese patients died from avian flu, so that this caused widespread panic in Southeast Asia.

   • Two Vietnamese patients died from avian flu, causing widespread panic in Southeast Asia.

3. After he wrote the letter, he put it to mail.

   • After writing the letter, he put it to mail.

4. As it was rather late, the rescue workers decided to quit.

   • It being rather late, the rescue workers decided to quit.
   • be 动词如果省略，会使得 rather late 的角色不清晰

5. After it was redecorated, the house looks more comfortable.

   • Redecorated, the house looks more comfortable.
   • After being redecorated, the house looks more comfortable.
   • After the redecoration, the house looks more comfortable.
   • 尽管过去分词具有被动暗示，但我们也可以借助 being 来突出被动式

6. The case is closed now.

   • The case is being closed now.
   • 借助 being 是为了强调进行的状态，并进行词类变化

7. After he has been a soldier for 10 years, the man is quite used to taking orders.

   • Having been a soldier for 10 years, the man is quite used to taking order.
   • 借助 having been 是为了强调完成的状态，并进行词类变化

8. After it had been robbed five times, the store finally installed a security system.

   • After having been robbed five times, the store finally installed a security system.
   • 介系词受词须是名词类，且动词片语要暗示被动，所以只能对助动词做词类变化

9. When he entered the classroom, the teacher greeted the students.

   • Entering the classroom, the teacher greeted the students.

10. The teacher who entered the classroom greeted the students.

    • The teacher entering the classroom greeted the students.
    • The teacher, entering the classroom, greeted the students.
    • 居于句中的减化，如果不用逗号隔开，则具有指示作用。若隔开，则可能修饰动词或整个句子

11. The teacher greeted the students entering the classroom.

    • 可能为关系子句的减化

12. The teacher greeted the students, entering the classroom.

    • 可能为副词子句的减化

减化为不定词片语

当子句的动词片语由语气助动词构成，可将其减化为不定词片语。注意由于不定词片语可承担角色的多样性，在减化后语义清楚的前提下就可以进行省略，而不必介意主句子句主词是否一致的问题。

1. The student studied hard (in order) to get a scholarship.
   • The student studied hard in order that he could get a scholarship.
2. The boy left home early so as to be in time for the concert.
   • The boy left home early so that he could be in time for the concert.
3. The air in the city is so polluted as to be dangerous to health.
   • The air in the city is so polluted that it may be dangerous to health.
4. The candidate made such an effort as to be sure of success.
   • The candidate made such an effort that he should be sure of success.
   • so … that / so … as to 引导的减化子句配合形容词或副词使用，其中 so 是程度副词
   • such … as to 配合名词片语使用，such 是前位限定词

减化为介系词片语

由于介系词的来源不同，所以我们需要分情况讨论。

补语为介系词片语

如果副词子句本来就是用介系词片语当主词补语，那么减化后剩下的就是这个介系词片语。

1. While he is on duty, the officer never drinks.
   • While on duty, the officer never drinks.
2. If you are in doubt, look up the word in the dictionary.
   • If in doubt, look up the word in the dictionary.

连接词做介系词

因为副词子句的连接词可能同时兼任介系词的词性。所以当子句减化后，连接词就会自动转化为介系词。

1. That man used to be a gangster before he joined the army.
   • That man used to be a gangster before joining the army.
   • 减化后动词片语转化为动名词片语。
2. After he was nominated for the Oscar, the actor became highly sought after.
   • After being nominated for the Oscar, the actor became highly sought after.
   • After the nomination for the Oscar, the actor became highly sought after.
   • After the Oscar nomination, the actor became highly sought after.
   • 介系词后需要名词类，可以直接使用分词片语或做词类转化
3. I have been very busy since I returned from Bali.
   • I have been very busy since returning from Bali.
4. The fruit doesn’t turn red until it is completely ripe.
   • The fruit doesn’t turn red until being completely ripe.
5. The man can’t find a job easily, for he has a criminal record.
   • The man can’t find a job easily, for having a criminal record.
6. As I am a scientist, I believe in concrete facts only.
   • A scientist, I believe in concrete facts only.
   • 注意在意思清楚的前提下，也可直接省略连接词

连接词改写为介系词

在不产生歧义和曲解原意的基础上，可以将连接词改写为意思相近的介系词。

下面是一些例子：

1. he girl is determined to marry her boyfriend although her parents object strongly.
   • The girl is determined to marry her boyfriend despite her parents’ strong objection.
2. The little resort town is crowded because there has been an influx of tourists.
   • The little resort town is crowded, with an influx of tourists.
3. When she heard her child cry, the woman rushed into the bedroom.
   • On hearing her child cry, the woman rushed into the bedroom.
4. If the river rises above the red line, the village nearby will be evacuated.
   • In case of the river rising above the red line, the village nearby will be evacuated.

减化为其他

如果副词子句本来就有 be 动词或其他连缀动词，且后面跟的主词补语时名词或形容词。那么减化后就只剩下那部分补语了。如果认为句子结构不清晰，可以借助 being 来强调结构。

1. Although he is a famous professor, my friend is extremely naive in practical matters.
   • Although a famous professor, my friend is extremely naive in practical matters.
2. When he was younger, the man could play mahjong for three days straight.
   • When younger, the man could play mahjong for three days straight.
   • Younger, the man could play mahjong for three days straight.
3. I will do it alone, if that is necessary.
   • I will do it alone, if necessary.

关系子句减化

关系子句的减化方法与上两种子句一致。因为关系代名词是先行词的重复，所以关系子句减化后，原本的连接词，包括关系代名词、关系副词都不会被留下来。

如果子句不含语气助动词，那么将子句的动词片语转化为分词，作为形容词修饰主词。如果子句动词片语是语气助动词，则需要将其改为不定词片语。

减化为分词

当关系代名词是关系子句的主词时，我们可以将其减化为分词。

1. The man who wants to see you is waiting outside.
   • The man wanting to see you is waiting outside.
2. Anyone that has visited Bali once will want to return.
   • Anyone having visited Bali once will want to return.
3. Do you know the girl who is sitting next to John?
   • Do you know the girl sitting next to John?
4. Grapes that are grown in the Champagne area make the best wines.
   • Grapes grown in the Champagne area make the best wines.
   • 原本的关系子句具有指示作用。且减化后剩下过去分词片语，具有被动的暗示
5. A student who has been trained at this school is guaranteed to excel in any exam.
   • A student having been trained at this school is guaranteed to excel in any exam.
   • A student trained at this school is guaranteed to excel in any exam.
   • 对于过去完成式，我们可以借助助动词 have，或过去分词自带的完成暗示

减化为复合形容词

当关系代名词是关系子句的主词时，我们可以将其减化为复合形容词。

关系子句是形容词类，处于先行词之后。而形容词只能出现在名词片语和补语中。所以我们可以将关系子句减化为一个复合形容词，然后像使用单一形容词那样使用它。

1. “Big John” is a machine. + The machine drills tunnels.
   • “Big John” is a machine that drills tunnels.
   • “Big John” is a tunnel-drilling machine.
2. That magazine is for women. + That magazine looks beautiful.
   • That magazine which looks beautiful is for women.
   • That beautiful-looking magazine is for women.
3. I love these high peaks. + These high peaks are covered with snow.
   • I love these high peaks, which are covered with snow.
   • I love these high, snow-covered peaks.

减化为形容词

当关系代名词是关系子句的主词，且关系子句为 S + V + C 时，主词补语可能为名词或形容词。减化后就只剩补语成分了。注意到如果是名词，减化后的句子就是所谓的同位格。

1. A chimpanzee is an animal that is capable of some reason.
   • A chimpanzee is an animal capable of some reason.
2. This movies features Tom Hanks, who is my favorite movie star.
   • This movies features Tom Hanks, my favorite movie star.

减化为不定词片语

当子句包含语气助动词，可将其减化为不定词片语。此时不必关心关系代名词是否为关系子句的主词，只要不曲解原意，就可进行减化。

1. This is not the right thing which you should do.
   • This is not the right thing to do.
2. If you like Cantonese food, I know just the place where you can go.
   • If you like Cantonese food, I know just the place to go.
3. There’s still one more person we must notify.
   • There’s still one more person to notify.
4. There’s still one more person who must be notified.
   • There’s still one more person to be notified.
   • 被动语态
5. I’m looking for a motorcycle that my wife can ride.
   • I’m looking for a motorcycle for my wife to ride.
   • 使用 for 交代不定词片语的主词，否则会产生歧义