否定形式：am/is/are+not;此时态的谓语动词若为行为动词，则在其前加don't,如主语为第三人称单数

He likes football.
He doesn't like football.

am/is/are+not

I am not a teacher.
You are not a student.
He is not a doctor.

谓语动词若为行为动词

I don't go to school.

She doesn't go to school.

有一个特别的have
它可直接加not

当它作为助动词时,可直接加not,

当它作为行为动词时,解释为吃,有,
可在后加not,也可在前边加 don't