John Cowan sends me this link (prepublication draft of David Willis, Christopher Lucas and Anne Breitbarth, “Comparing Diachronies of Negation,” from their The History of Negation in the Languages of Europe and the Mediterranean, Vol. 1: Case Studies), adding:
It’s a fairly accessible paper (if you skip the formal-syntax section in pp. 6-7) that talks about how negation elements are replaced over time with new negation elements. In English, “ic ne secge” > “I ne seye not” > “I say not” > “I don’t say”, where the preverbal “ne” gets supplemented by not < ne-wiht ‘nothing’, which then replaces it and moves forward to attach to the new auxiliary, more or less re-creating the original situation. There are discussions of Germanic, Romance, Baltic, Slavic, Uralic, and Semitic languages, with lots of those complicated details we both love.
Definitely LH material; thanks, JC!