在英语语法中，定语从句是一种用来修饰名词或代词的句子结构。它通常由关系代词（如who, whom, whose, which, that）或关系副词（如where, when, why）引导，并且紧接在被修饰的名词或代词之后。通过学习和理解定语从句，我们可以更准确地表达复杂的思想，使语言更加生动和具体。

下面是一些常见的定语从句例子：

1. The book that I bought yesterday is very interesting.

- 在这个句子中，“that I bought yesterday” 是一个定语从句，用来修饰先行词“the book”。这里的关系代词“that”指代“book”，并且在从句中作宾语。

2. The man who lives next door is my teacher.

- 这里，“who lives next door”是一个定语从句，用来描述“the man”。关系代词“who”在从句中充当主语。

3. The movie whose main character is a detective is my favorite.

- 在这个例子中，“whose main character is a detective”是一个定语从句，用来修饰“the movie”。关系代词“whose”表示所属关系。

4. This is the park where we had our first date.

- 定语从句“where we had our first date”修饰先行词“the park”。关系副词“where”在从句中作地点状语。

5. Yesterday was the day when we graduated from college.

- 定语从句“when we graduated from college”修饰“the day”。关系副词“when”在从句中作时间状语。

6. The reason why he left early is unknown to me.

- 定语从句“why he left early”修饰“the reason”。关系副词“why”在从句中作原因状语。

7. The car which is parked outside belongs to my neighbor.

- 定语从句“which is parked outside”修饰“the car”。关系代词“which”在从句中作主语。

8. She is the girl whose handwriting is neat and clear.

- 定语从句“whose handwriting is neat and clear”修饰“the girl”。关系代词“whose”表示所属关系。

9. The building where the library is located is very old.

- 定语从句“where the library is located”修饰“the building”。关系副词“where”在从句中作地点状语。

10. The time when we spent together was unforgettable.

- 定语从句“when we spent together”修饰“the time”。关系副词“when”在从句中作时间状语。

以上这些例子展示了定语从句的不同形式及其在实际应用中的灵活性。掌握定语从句不仅可以帮助我们更好地组织语言，还能让我们的表达更具逻辑性和连贯性。希望这些例子能对你有所帮助！