Formal:
* 我 不 (wǒ bù) - This is the most basic and common way to say "I'm not."
* 我 没有 (wǒ méiyǒu) - This means "I don't have" and can be used to express the lack of something, for example, "I'm not hungry" (我 没有 饿).
* 我 不是 (wǒ búshì) - This means "I'm not" and is used to negate a statement about your identity or characteristics, for example, "I'm not a doctor" (我 不是 医生).
Informal:
* 我没 (wǒ méi) - This is a shortened form of "我没有" and is commonly used in casual conversation.
* 我 不 (wǒ bù) - This is the same as the formal "我 不," but is often used in informal contexts.
Examples:
* I'm not hungry. (我 没有 饿 / 我 没 饿)
* I'm not a student. (我 不是 学生)
* I'm not going. (我 不 去)
Remember: The choice of "不" or "没有" depends on the situation and what you want to express. "不" is more general, while "没有" emphasizes the lack of something.
It's also important to note that the tone of your voice can also influence the meaning of the phrase.