No: (a) as a reply to a question, rhetorical question, request, or demand; certes nai, nai certes, nai forsoth, nai goddot, nai parde, nai sothli, certainly not, of course not; -- also reduplicated……
(a) As an affirmative reply to a direct or an indirect question: yes; seien ye
(b) as an affirmation of the truth or correctness of an assertion, a proposition, etc.: that is right, it is so, yes;……