【定语从句例句】在英语学习中，定语从句是一个非常重要的语法知识点，它用于修饰名词或代词，使句子更加丰富和具体。定语从句通常由关系代词（如 who, whom, whose, which, that）或关系副词（如 when, where, why）引导。以下是对常见定语从句结构的总结，并附有典型例句，便于理解和记忆。
一、定语从句基本结构
| 引导词 | 用法说明 | 例句 |
| who | 指人，作主语或宾语 | The man who is speaking is our teacher. |
| whom | 指人，作宾语 | The girl whom you met yesterday is my sister. |
| whose | 表示所属关系，指人或物 | The boy whose bag was lost is in the office. |
| which | 指物，作主语或宾语 | The book which I bought yesterday is very interesting. |
| that | 指人或物，作主语或宾语 | The person that called me is my friend. |
| when | 指时间，作状语 | The day when we met will never be forgotten. |
| where | 指地点，作状语 | This is the house where I was born. |
| why | 指原因，作状语 | Do you know the reason why she left? |
二、定语从句的使用规则
1. 关系代词不能省略：当关系代词在从句中作宾语时，有时可以省略，但若在句首或作为主语，则不可省略。
- 正确：The man who is standing there is a doctor.
- 正确：I know the man (who) you mentioned.
2. 非限制性定语从句：用逗号隔开，表示补充说明，不能用 that 引导。
- 例句：My brother, who lives in Shanghai, is coming to visit us.
3. 关系代词与关系副词的选择：
- 若先行词是“人”，可用 who/whom/whose。
- 若先行词是“物”，可用 which/that。
- 若先行词是“时间、地点、原因”，则用 when/where/why。
三、典型例句汇总
| 句子 | 解析 |
| The student who won the prize is from Beijing. | who 引导定语从句，修饰 student |
| The book which I read last night was very boring. | which 引导定语从句，修饰 book |
| The place where we met is beautiful. | where 引导定语从句，修饰 place |
| The reason why he was late is unknown. | why 引导定语从句，修饰 reason |
| My father, who is a teacher, loves reading. | 非限制性定语从句，补充说明 father |
四、小结
定语从句是英语中表达复杂信息的重要工具，掌握其结构和用法有助于提高语言表达的准确性和多样性。通过不断练习和积累，可以更灵活地运用定语从句，使写作和口语表达更加自然流畅。
希望以上内容对你的英语学习有所帮助！
