For non verbal negation, do you use “ní”? For example, would “Not now” be “ní anois”? If yes, does it still trigger lenition, so for example “not yet” would be “ní gho fóill”?
Ní causes lenition as a verbal particle. If you don’t use a verb, ní is most likely a form of the copula. So, there’s no lenition. E.g. Ní anois = Not now. It’s an ellipsis of a full sentence, e.g.: Ní anois (atá mé ar meisce ) = (It’s) not now (that I’m drunk.)
Or: Ní go fóill = Not yet. -> Ní go fóill atá mé tagtha. = It’s not yet that I have arrived.