过去分词是动词的一种形式，常用于被动语态、完成时态及修饰名词等。以下是其五种主要用法和语法特点：
| 用法 | 说明 | 例句 |
| 被动语态 | 构成“be + 过去分词”结构 | The book was written by him. |
| 完成时态 | 构成“have/has + 过去分词” | She has finished her homework. |
| 状语 | 表示原因、时间或条件 | Given the time, we started early. |
| 定语 | 修饰名词，表示被动或完成 | The broken window needs repair. |
| 表语 | 作系动词后的表语，表示状态 | The door is locked. |
掌握这些用法有助于更准确地理解和运用英语句子结构。
