定语从句四大易错点：关系代词做宾语可省略、which不配人、从句动词跟先行词、whose表所属
引言
定语从句不难，难在细节：关系代词什么时候能省略？whose 怎么用？从句动词为什么总选错？把这些易错点一次讲透，定语从句题基本就稳了。
核心概念：关系代词在从句里做主语还是宾语
```text
做主语：关系代词不能省略
The girl who is singing is my sister.
（who 在从句中做主语，不能省）
做宾语：关系代词可以省略
The movie (that/which) we watched yesterday is great.
（that 在从句中做宾语，可省）
```
易错点一：which 不配人，who 不指物
```text
The man which helped me. ✗ 错误
The man who helped me. ✓ 正确
The house who we visited. ✗ 错误
The house which we visited. ✓ 正确
```
易错点二：从句动词跟着先行词
```text
先行词是单数 → 从句动词用单数
先行词是复数 → 从句动词用复数
The boy who is reading is my friend.（boy 单数 → is）
The students who are reading are in Class One.（students 复数 → are）
注意：不要被关系代词干扰，看先行词！
```
易错点三：whose 表示"……的"
```text
whose = 谁的（先行词的）
先行词是人：The girl whose mother is a teacher is my friend.
先行词是物：The house whose windows face south is ours.
（窗户属于房子 → whose windows）
```
易错点四：做宾语时关系代词可省略
```text
The book that I borrowed is interesting.
= The book I borrowed is interesting.（that 可省）
但做主语不能省：
The book that is on the desk is mine.
≠ The book is on the desk is mine. ✗ 错误（that 不能省）
```
实战练习
```text
- The man ______ we met yesterday is my uncle.
→ that/whom（做宾语，可省略）
- This is the pen ______ I lost last week.
→ that/which（指物，做宾语，可省）
- The students ______ are playing basketball are in Grade Nine.
→ who（先行词复数 → who are）
- The woman ______ daughter is a doctor is my neighbor.
→ whose（所有格）
```
总结
```text
关系代词做主语不能省，做宾语可省
which 不配人，who 不指物
从句动词跟先行词的单复数
whose 表"……的"，人、物都适用
口诀：主语不能省，宾语可省略
动词跟先行，whose 表所属
```
```text
今日小抄：
The movie (that) we watched yesterday is great.
The girl whose mother is a teacher is my friend.
做主语 that 不能省，做宾语 that 可省
students 复数 → who are reading
```