分词状语从句
B2 Participle clauses 46 / 50
概要
分词状语从句用分词（-ing 形式、过去分词，或者 having + 过去分词）把一个较长的从句压缩成几个词。这是一种简洁、更正式的表达时间、原因或定语从句的方式，书面语中很常见。
规则
分词状语从句替代的是和主句共享主语的完整从句。你去掉主语和连接词，改用分词。
- 现在分词（-ing）= 主动含义。 用来表示同一主语做的两个动作（同时发生，或一个引起另一个），或用来简化主动语态的定语从句。
- Feeling tired, I went to bed. (= Because I felt tired…)
- The man standing at the door is my uncle. (= the man who is standing…)
- 过去分词（-ed / 第三形式）= 被动含义。 用来简化被动语态的从句。
- Built in 1850, the bridge still stands. (= the bridge which was built…)
- Shocked by the news, she sat down. (= Because she was shocked…)
- 完成分词（having + 过去分词）表示这个动作明显早于主句的动作。
- Having finished dinner, we went out. (= After we had finished dinner…)
分词状语从句也可以放在主句后面：跟在后面的 -ing 从句通常说明主语当时同时在做什么（She stood at the window, waiting for the taxi），跟在后面的 having (been) + 过去分词 仍然表示更早发生的动作（We left early, having seen the film before）。
黄金法则： 分词隐含的主语必须和主句的主语一致。如果不一致，就会出现让人费解的“悬垂分词”。
- 错误：Walking home, the rain started.（可不是雨在走路！）
- 正确：Walking home, I got caught in the rain.
构成否定式，把 not 放在分词前面：Not knowing the way, we asked a local.
形式与结构
| 类型 | 形式 | 含义 | 替代 |
|---|---|---|---|
| 现在分词 | 动词 + -ing | 主动，同时／因果 | because / as / while / who + 主动态动词 |
| 过去分词 | 第三形式（-ed / 不规则） | 被动式 | because / which / who + 被动态动词 |
| 完成分词 | having + 第三形式 | 更早的动作（主动） | after / because + had done |
| 完成被动分词 | having been + 第三形式 | 更早的动作（被动） | after it had been done |
| 功能 | 完整分句 | 分词状语从句 |
|---|---|---|
| 原因 | Because she didn’t have a ticket, she waited outside. | Not having a ticket, she waited outside. |
| 时间 | After he locked the door, he left. | Having locked the door, he left. |
| 定语从句（主动） | the woman who lives next door | the woman living next door |
| 定语从句（被动） | the letters that were sent yesterday | the letters sent yesterday |
例句
| English | 说明 |
|---|---|
| Hearing the alarm, everyone left the building quickly. | 现在分词 = 同一主语的两个动作，几乎同时发生。 |
| Not feeling well, Sam stayed home from work. | 原因；not 放在 -ing 形式前面。 |
| The students waiting outside soon got cold. | 简化了 who were waiting；主动语态的定语从句。 |
| Written in plain English, the report was easy to read. | 过去分词 = 被动（which was written）。 |
| Frightened by the storm, the dog hid under the bed. | 过去分词表示原因（because it was frightened）。 |
| Having spent all her savings, she had to find a job. | 完成分词 = 花钱这件事明显发生在前。 |
| Having been warned twice, he finally slowed down. | 完成被动分词；警告发生在他减速之前。 |
| The road connecting the two towns is finally open. | 主动语态的定语从句简化成了 -ing 从句。 |
常见错误
- Walking to school, my bag broke. -> Walking to school, I noticed my bag had broken. ——分词的主语必须和主句一致（你的包可不会走路）。
- Build in 1850, the bridge still stands. -> Built in 1850… ——被动含义要用过去分词，不能用动词原形。
- Finishing dinner, we went out.（如果明显更早发生）-> Having finished dinner, we went out. ——已完成、更早发生的动作要用完成分词。
- Knowing not the answer, he stayed quiet. -> Not knowing the answer… ——否定词 not 要放在分词前面。
- Shocking by the news, she sat down. -> Shocked by the news… ——她是受到冲击的一方（被动），所以要用过去分词。
学习提示
- 检测悬垂分词的方法：-ing 这个动作的执行者必须是主句的主语，而不只是离它最近的名词。Turning the corner, the shop…? 不对——要改写成一个人作主语。
- -ing = 主语主动做这件事（主动）；过去分词 = 主语被动接受这件事（被动）。问自己：“这里的主语是主动的还是被动的？”
- 只有当“更早发生”这一点确实重要时，才用 having + 过去分词；否则一个普通的 -ing 从句就够了。
- 分词状语从句听起来正式、书面化。在日常口语中，用 because、after 或 who 构成的完整从句往往更自然。