ναί
I. used in strong affirmation, "yea, verily", Lat. nae, Hom., attic; in Hom. mostly followed by δή.
2. ναὶ μά in oaths, "yea by..", ναὶ μὰ τόδε σκῆπτρον Il.; μά is sometimes omitted, ναὶ τὰν κόραν Ar.; ναὶ πρὸς θεῶν Eur.
II. in answers, alone, "aye, yes", τοῦτ᾽ ἐτήτυμον; answ. ναί Aesch.; ναί, ναί Ar.