What are some examples of negators that have a known (or even conjectured) etymology? What kinds of non-negative meanings can develop into negative meanings?
The etymologizable negators I know of all arise from a kind of syntagm where a negative is used together with some other element, and that element then takes on the negative meaning, with the original negator sometimes disappearing. Examples are French pas < 'step', personne < 'person'; Ancient Greek ou < 'life'; and English not < ne wight 'no creature/thing' (where the original negator n- has remained).
Are there other etymological pathways which can result in negators? I'm interested in any item which falls broadly under the "negative" umbrella: not just verbal negators, but nominal ones (e.g. German kein/Dutch geen), negative predicators (e.g. Hungarian nincs 'is not', Hebrew eyn 'there is not'), etc.