Although 不(bù) and 没(méi) serves to negate, they emphasize different aspect.
There are three functions of 不(bù):
1. To negate one’s willingness. For example,
1)我不想去学校
Wǒ bùxiǎng qù xuéxiào
I don’t want go to school
‘I don’t want to go to school.’
2. To negate one’s habit or things that usually happen. For example,
2)我不抽烟
Wǒ bù chōuyān
I don’t smoke
‘I don’t smoke.’
3. To negate people or things own the certain property and state. For example,
3) 他不高
Tā bù gāo
He not tall
‘He is not tall.’
There are two functions of 没(méi):
1. To negate the event is already happened. For example,
4) 他没参加会议
Tā méi cānjiā huìyì
He not attend conference
‘He didn’t attend the conference.’
2. To negate the change of the property or state. For example,
5) 他没胖
Tā méi pang
He not fat
‘He doesn’t become fat.’
