Chinese uses different forms for negative action, depending on if the action is in the perfect aspect of a tense or the simple tense.
Chinese Negation没有 【méiyǒu】or its shorten form 没【méi】has several meanings depending on the grammar structure they use, as follows:
a. It means “not” for没有【méiyǒu】+ Verb. It’s generally used for the negative of the past tense.
b. It means “has/have not done yet” for 还【hái】+ 没有 【méiyǒu】+ Verb. It’s generally used for the negative of the present perfect tense.
c. It means “not have” for 没有【méiyǒu】+ Noun. Generally, it’s used for the negative of the past tense, present tense and future tense.
Negation In Chinese不 【bù】means “not” when it’s used before verbs to negate them. It’s generally used for present tense and future tense whereas 还【hái=still】+不【bù=not】+ Verb means “still do/does not”, it’s generally used for present tense.
从来没有 【cónglái méiyǒu=has/have never, never】…… 过【guò】or its shorten form从来没 【cónglái méi】…… 过【guò】is used for things you have not ever experienced. It allows for the possibility of something occurring in the future.
从来不 【cónglái bù=would never, always not】is used for would never happen. It doesn’t allow for the possibility of something occurring in the future.