ἀλλά
Etym. Conjunct., properly neut. pl. of ἄλλος (with changed accent)
"otherwise, but", stronger than δέ:
I. to oppose single clauses, "but", Lat. autem, the preceding clause being negat., οὐ μόνον ἅπαξ, ἀλλὰ πολλάκις Plat.; so, οὐχ (or μὴ) ὅτι, οὐχ (or μὴ) ὅπως, are followed by ἀλλά or ἀλλά καὶ..., "not only"..., "but"...
2. after a negative ἀλλά sometimes = ἀλλ᾽ ἤ, "except, but", ἔπαισεν οὔτις ἀλλ᾽ ἐγώ Soph.
II. to oppose whole sentences, "but, yet", Lat. at:— used by Hom., with imperat. or subj., to remonstrate, encourage, persuade, like Lat. tandem, ἀλλ᾽ ἴθι, ἀλλ᾽ ἄγε, ἀλλὰ ἴωμεν, Hom.
III. joined with other Particles, ἀλλ᾽ ἄρα, or, ἀλλ᾽ οὖν, "but then, however", Hdt., etc.
2. ἀλλὰ γάρ, Lat. enimvero, "but really, certainly", attic
3. ἀλλ᾽ ἦ in questions, Lat. an vero? ergo? Plat.: cf. ἀλλ᾽ ἤ (suo loco).