一般现在时——第三人称单数动词变化全攻略
一、什么是"第三人称单数"？
在英语中，第三人称单数指的是： - 人称代词：he（他）、she（她）、it（它） - 单个的人名/称呼：Tom、My father、Miss Wang - 单个的事物：The cat、My book、This school
核心规则：主语是第三人称单数时，一般现在时的动词要加 -s 或 -es。
二、动词变化规则
| 规则 | 动词原形 | 第三人称单数形式 |
|---|---|---|
| 一般情况直接加-s | play, like, read | plays, likes, reads |
| 以s/x/sh/ch/o结尾加-es | go, do, watch, wash | goes, does, watches, washes |
| 辅音字母加y → 变y为i加-es | study, fly, cry | studies, flies, cries |
| 特殊变化 | have | has |
三、三种句型结构
1. 肯定句
主语 + 动词第三人称单数 + 其他
- He plays football every Sunday.
- My mother goes to work by bus.
- The cat likes fish.
2. 否定句（用doesn't + 动词原形）
主语 + doesn't + 动词原形 + 其他
- He doesn't play football every Sunday. ❌ 不能说 He doesn't plays
- She doesn't like apples.
3. 一般疑问句（句首加Does + 动词原形）
Does + 主语 + 动词原形 + 其他？
- Does he play football every Sunday?
- Does your mother go to work by bus?
肯定回答：Yes, he does. 否定回答：No, he doesn't.
四、常考易错点
-
❌ He like apples.（漏了-s） ✅ He likes apples.
-
❌ She doesn't likes milk.（doesn't后用动词原形！） ✅ She doesn't like milk.
-
❌ Does he plays basketball?（疑问句动词要用原形！） ✅ Does he play basketball?
-
❌ Tom go to school every day. ✅ Tom goes to school every day.
五、例题精练
【例题1】 用所给词的适当形式填空。
My sister __ (study) English every morning.
解析：My sister是第三人称单数，study以辅音+y结尾，变y为i加-es。 答案：studies
【例题2】 改否定句。 Mike reads books in the library.
解析：主语Mike是第三人称单数，否定句用doesn't + 动词原形。 答案：Mike doesn't read books in the library.
六、实用口诀
一般现在时，三单要注意； 肯定加-s/es，否定疑问用does； does后面原形跟，千万别再加变化； 每天/经常/总是，看见就用一般时。
标志词：every day, often, usually, always, sometimes