Where does “no-” come from?

no- (Middle Irish) comes from Old Irish no-, from Proto-Indo-European nū — now.

Ancestry of “no-”, step by step

StepLanguageWordMeaning
1Old Irishno-Used to support prototonic verb forms where no...
2Proto-Indo-Europeannūnow
Every word from Proto-Indo-European nū →Every word from Old Irish no- →