ἆρα
Perseus. "particle introducing a question"
interrog. Particle, in accent and sense a stronger form of ἄρα:
1. when it stands alone it usually expects a negative answer, like Lat. num? attic; so ἆρα μή; "num vero?" Aesch.:—for an affirmative answer, ἆρ᾽ οὐ; ἆρ᾽ οὐχί; "nonne vero"? is used, Soph., etc.
2. in prose, ἆρα almost always stands first in the sentence.