【复合句是什么从句可以分为哪几种】在英语语法中，复合句是由两个或两个以上意义相关的独立分句（主句）通过连词连接而成的句子。每个主句都能独立表达完整的意思。而从句则是不能单独成句、必须依附于主句的句子成分，它在句中充当名词、形容词或副词的作用。
从句根据其在句子中的功能不同，可以分为以下几类：
一、名词性从句
名词性从句在句中起名词作用，可以作主语、宾语、表语或同位语。常见的引导词有：that, whether, if, what, who, whom, whose, when, where, why, how 等。
| 类型 | 功能 | 示例 |
| 主语从句 | 作主语 | That he passed the exam surprised everyone. |
| 宾语从句 | 作宾语 | I know that she is a teacher. |
| 表语从句 | 作表语 | The problem is that we don’t have enough time. |
| 同位语从句 | 解释说明名词 | The fact that he left early was unexpected. |
二、定语从句（关系从句）
定语从句用来修饰名词或代词，通常由关系代词（who, whom, whose, which, that）或关系副词（when, where, why）引导。
| 类型 | 引导词 | 示例 |
| 限制性定语从句 | that, which, who, whom, whose | The book that I bought is very interesting. |
| 非限制性定语从句 | which, who, whom, whose | My brother, who lives in Shanghai, is a doctor. |
三、状语从句
状语从句用于表示时间、原因、条件、目的、结果、让步、方式等，通常由从属连词引导。
| 类型 | 常见引导词 | 示例 |
| 时间状语从句 | when, while, before, after, since, until, as soon as | I will call you when I arrive. |
| 原因状语从句 | because, since, as, for | He stayed home because it was raining. |
| 条件状语从句 | if, unless, as long as, provided that | If it rains, we will stay indoors. |
| 目的状语从句 | so that, in order that | She studied hard so that she could pass the exam. |
| 结果状语从句 | so...that, such...that | He was so tired that he fell asleep immediately. |
| 让步状语从句 | although, though, even though, despite | Although it was cold, we went out. |
| 方式状语从句 | as, like, just as | Do as I tell you. |
四、其他特殊从句
除了上述三种主要从句外，还有一些特殊的从句类型，如：
- 强调句型：It is...that...结构，用于强调句子中的某个成分。
- 插入语从句：在句子中起到补充说明作用的从句。
- 省略从句：在某些情况下，从句中的部分成分可以省略。
总结
复合句是包含一个或多个从句的句子结构，从句根据其在句中的功能可分为名词性从句、定语从句和状语从句三大类。每种从句都有其特定的引导词和使用场景，在实际写作和阅读中需要准确识别和理解它们的作用。
| 从句类型 | 功能 | 引导词示例 |
| 名词性从句 | 作主语、宾语、表语、同位语 | that, whether, what, who, when, why |
| 定语从句 | 修饰名词或代词 | that, which, who, whose, when, where |
| 状语从句 | 表示时间、原因、条件等 | when, because, if, so that, although |
掌握这些从句的用法，有助于提高英语写作和理解能力，使语言表达更加丰富和准确。
