Chinese Basic 1
Ordering Food and Drink

Using 有

有 (yǒu) means 'to have' or 'to exist'. It is negated by 没 (méi) not 不 (bù). To ask if somebody has something you can ask:
你有没有 x? Nǐ yǒu méi yǒu x? 'Do you have x?'

For example:
有没有中国白酒? Yǒu méi yǒu Zhōngguó bái jiǔ? 'Do you have Chinese liqour?'
You could also say: 有中国白酒吗?

These questions are often used interchangably. The difference is that by asking a 吗 - question the speaker expects the answer to be 'yes', while the '有没有' question implies no such assumption.