動詞單三變化規則
1.一般情況下，直接在動詞詞尾+s：
2.以s，x，sh，ch，o結尾的動詞，在詞尾+ es：
3.以輔音字母+ y 結尾的動詞，先把y變為i，再加es：
4.不規則動詞（特殊情況）：
變否定句時遵循的規則
含有動詞第三人稱單數形式的句子變否定句時，要在動詞前面加上doesn’t 或does not，動詞的第三人稱單數形式要還原成原形：格式為doesn’t/does
not+ 動詞原形，如：
He goes to school at six in the morning. (變否定句) 就變換為：
He doesn't go to school at six in the morning.
2.變一般疑問句：把含有動詞第三人稱單數形式的變成一般疑問句時，要借用助動
詞does，如：
She goes home at five every day.（變疑問句）就變換為：
Does she go home at five every day? -- Yes，she does./No，she doesn’t.
哪些主語是第三人稱單數
1.人稱代詞he，she，it；
如：He likes watching TV.
She has lunch at twelve.
It looks like a cat.
2.單個人名、地名或稱呼作主語；是第三人稱單數。如：
Han Mei looks like her mother.
Beijing is in China.
Uncle Wang often makes cakes.
3.單數可數名詞或
this/that/the+單數可數名詞作主語時，是第三人稱單數；
A horse is a useful animal.
This book is yours.
That car is red.
4、不可數名詞作主語時為第三人稱單數。如：
The milk is in the glass.
The bread is very small.
The water is very cold.