第十三章复合句

一、复合句核心定义

复合句（compound sentences）是中級句型核心，由两个以上限定从句通过对等连接词（主要为 and、or、but）连接构成，从句间地位平等（对等从句）。

限定从句：含限定动词（有人称、时态变化，可独立构成单句），如“He understands”“He did the wrong thing”。
非限定从句：仅含非限定动词（现在分词、过去分词、动名词、不定词），无法独立成句，如“his girlfriend’s spending so much time”。

层次	定义	示例
初级：单句	单个限定从句，结构完整	We are sitting here in the sun.
中级：复合句	两个以上限定从句连接（复合句/复句）	We are sitting here in the sun, and we can see snow-covered hills.
高级：减化从句	仅留一个限定从句，其余改为非限定从句	Sitting here in the sun, we can see snow-covered hills.

层次

定义

示例

初级：单句

单个限定从句，结构完整

We are sitting here in the sun.

中级：复合句

两个以上限定从句连接（复合句/复句）

We are sitting here in the sun, and we can see snow-covered hills.

高级：减化从句

仅留一个限定从句，其余改为非限定从句

Sitting here in the sun, we can see snow-covered hills.

可连接主词、动词、宾语、补语、修饰语等任何对等部分，要求构造与内容对称：

直接连接两个以上完整限定从句，多从句时用逗号分隔，最后一个从句前加 and：

两从句：Everyone was in the hall, and the door had been closed.
三从句：Most of us were in the hall, the doors had been closed, and the lights were out.

为明确逻辑关系，可使用相关词组，对称要求更严格（A 与 B 需词类/结构一致）：

both A and B（两者都）：He spoke both to George and to me.
either A or B / neither A nor B（要么/既不）：Either he dislikes our hair, or we offended him.
not only A but also B（不仅…而且）：Gold jewelry looks not only beautiful but also elegant.

对等从句中重复元素可省略，但需保证剩余部分对称、句意清晰：

原句：We always worked together and we always played together.
省略后：We always worked and played together.
注意：若重复元素为宾语且角色不同（如一个为介系词宾语，一个为动词宾语），不可省略关键介词，如：
- 错误：Smoking may slow the growth and harm the fetus.
- 正确：Smoking may slow the growth of and harm the fetus.

核心错误为“连接词前后元素词类/结构不一致”，需重点规避：

错误：War is destructive, wasteful, and ultimately a futile deed.（前两词为形容词，后为名词短语）
正确：War is destructive, wasteful, and ultimately futile.
错误：The Yangtze River, the most vital source… and important as a transportation conduit…（前为名词短语，后为形容词）
正确：The Yangtze River, the most vital source… and an important transportation conduit…