在初中英语学习中，定语从句是一个重要的语法知识点。它能够帮助我们更准确地表达事物之间的关系，使得句子更加丰富和具体。为了更好地掌握这一语法点，下面提供了一些定语从句的专项练习题，并附有详细答案解析，供同学们参考。
一、选择题
1. The boy ________ is standing under the tree is my cousin.
A. who
B. which
C. what
D. whom
答案：A
解析：“who”用于指代人，在定语从句中作主语。
2. This is the book ________ I bought yesterday.
A. that
B. whose
C. where
D. when
答案：A
解析：“that”可以用来指代物或人，在定语从句中作宾语或主语。
3. Do you know the girl ________ hair is long?
A. whose
B. who
C. whom
D. which
答案：A
解析：“whose”表示所属关系，修饰名词“hair”。
4. The man ________ gave me the book is my teacher.
A. which
B. who
C. whom
D. what
答案：B
解析：“who”用于指代人，在定语从句中作主语。
5. The school ________ we visited last week is very famous.
A. that
B. whose
C. where
D. when
答案：A
解析：“that”可以用来指代地点，在定语从句中作宾语。
二、填空题
6. The girl ________ mother works in the hospital is my friend.
答案：whose
解析：“whose”表示所属关系，修饰名词“mother”。
7. The book ________ you borrowed from the library is very interesting.
答案：that/which
解析：“that”或“which”都可以用来指代物，在定语从句中作宾语。
8. The house ________ windows face south is mine.
答案：whose
解析：“whose”表示所属关系，修饰名词“windows”。
9. The boy ________ I talked to just now is Tom.
答案：whom
解析：“whom”用于指代人，在定语从句中作宾语。
10. The city ________ I was born is Shanghai.
答案：where
解析：“where”用于指代地点，在定语从句中作状语。
三、改写句子
11. The girl is my friend. She has long hair.
改为定语从句：
The girl whose hair is long is my friend.
12. The book is on the table. You bought it yesterday.
改为定语从句：
The book that you bought yesterday is on the table.
13. The man is our teacher. He is standing over there.
改为定语从句：
The man who is standing over there is our teacher.
14. The school is very beautiful. We visited it last year.
改为定语从句：
The school that we visited last year is very beautiful.
15. The car is mine. Its color is red.
改为定语从句：
The car whose color is red is mine.
通过以上练习，希望大家能够熟练掌握定语从句的基本用法。定语从句不仅在考试中频繁出现，还能让我们的写作和口语表达更加地道和生动。加油！
