三单句型转换：否定句/一般疑问句/特殊疑问句，does 后面动词为什么要还原？
引言
三单变形规则背熟了，一考句型转换还是错：否定句、疑问句都要靠助动词 does，而且动词要还原成原形。
核心规则：does / doesn't 承担三单变化
```text
三单主语 + 实义动词的否定句：doesn't + 动词原形
三单主语 + 实义动词的一般疑问句：Does + 主语 + 动词原形
does 和 doesn't 已经带了三单，后面的动词不能再加 s
```
否定句：doesn't + 动词原形
```text
John drinks a cup of coffee every morning.
John doesn't drink a cup of coffee every morning.
（drinks 的 s 被 doesn't 拿走，还原 drink）
```
一般疑问句：Does 提前，动词还原
```text
She plays on the playground after school.
Does she play on the playground after school?
（play 还原，不再加 s）
```
```text
肯定回答：Yes, she does.
否定回答：No, she doesn't.
```
特殊疑问句：疑问词 + does + 主语 + 动词原形
```text
She plays on the playground after school.
对划线部分 plays...（她做的事）提问：
What does she do after school?
（what + does + she + do）
```
常见错误对照
```text
错误 正确
He doesn't likes apples. He doesn't like apples.
Does he watches TV? Does he watch TV?
What does she does? What does she do?
```
实战练习
```text
- Tom likes swimming. 变否定句
→ Tom doesn't like swimming.
- She reads English every morning. 变一般疑问句
→ Does she read English every morning?
- My mother watches TV every evening. 对划线部分提问
→ What does my mother do every evening?
```
总结
```text
doesn't / does 已经承担三单，后面动词一律还原原形
句型转换三步：找主语 → 定 does → 动词还原
```
```text
今日小抄：
John doesn't drink coffee.
Does she play after school? — Yes, she does.
What does she do after school?
```