关系代词是英语中一个重要的语法部分，用来连接两个句子或者在一个句子中描述人或物之间的关系。以下是关系代词的20个简单例句：
- The girl who is singing is my sister.（唱歌的女孩是我的妹妹）
- The book that I read yesterday was very interesting.（我昨天读的那本书非常有趣）
- The man whom I saw at the party was my old friend.（我在聚会上见到的那个男人是我的老朋友）
- The dog whose tail is wagging is very friendly.（摇尾巴的那只狗非常友好）
- The car which he bought last week is very expensive.（他上周买的那辆车非常昂贵）
- The woman whom I spoke to was very kind.（我跟那个女人说话很友好）
- The dress that she is wearing is very beautiful.（她穿的那条裙子非常漂亮）
- The boy whose bike was stolen is very upset.（那个自行车被偷的男孩很难过）
- The teacher who taught me math is retiring next year.（教我数学的老师明年退休了）
- The house which we visited last week was very big.（我们上周参观的那座房子非常大）
- The man whom I met earlier is a doctor.（我早些时候遇见的那个男人是个医生）
- The computer that I bought was very expensive.（我买的那台电脑非常昂贵）
- The cat whose fur is black and white is very cute.（黑白相间的那只猫非常可爱）
- The person who called me last night was my boss.（昨晚打电话给我的人是我的老板）
- The movie which we watched yesterday was very entertaining.（我们昨天看的那部电影非常有趣）
- The boy whom I helped with his homework got an A.（我帮忙做作业的那个男孩得了A）
- The cake that she baked was delicious.（她烤的那个蛋糕很好吃）
- The woman whose son is in my class is a teacher.（我班上那个男孩的妈妈是个老师）
- The restaurant which we went to last night had excellent food.（我们昨晚去的那家餐厅食物很棒）
- The man whom I saw on the street is a famous actor.（我在街上看到的那个男人是一位著名演员）
以上是关系代词的20个简单例句，希望对你们的英语学习能有所帮助！
