Assuming that languages do not create complexities in vain, the existence in Mandarin of two different propositional negation devices - via “bù”, an adverb, and “méi” or “méiyou” (verbs) - seems to point to relevant differences between the negated 'predications' and possibly between the ontological properties of the ‘states of affairs/events’ that such predications describe. However, what such difference(s) may be is as yet unclear to me.
The grammars of Mandarin I have seen all roughly say that the time interval at which the state of affairs/event is described as not holding/having occurred is relevant, and in particular that ‘méi’ is used to negate sentences describing events/states of affairs that were not the case in the past, whereas “bù” is used to negate sentences describing events/states of affairs that are not the case at present or will not be the case at some future time.
However, I see no valid ontological difference between non-events/non-states of affairs in that respect, nor any obviously relevant grammatical difference between the predications that must be negated with "bù" and "méi", respectively. [One of the complications is that there happens to be a unique Chinese stative verb "you3" sometimes meaning 'have', 'possess', 'exist [for somebody]', but also equivalent to 'yes', 'is the case', 'is true' in other cases, that must nowadays be negated with "méi(you)", not "bù", in spite of the fact that it obviously refers to a currently holding state of affairs. Another is that the adverb "hái", meaning 'yet' as in E. "not yet", can co-occur with (precede) both "bù" and "méi(you)", although the sentence in which it appears cannot possibly refer to a non-fact of a past world].
My question, then, is this: are there any other languages in which a comparable distinction exists between the way sentences must be negated depending on whether they describe non-events of the past or the non-past, respectively?