The Ancient Greek particle an, which encodes modal and irrealis semantics, canonically occurs once per clause. In the fifth century bce, however, we find cases where two tokens (or, more rarely, three) co-occur with the same verb. While this phenomenon has long been recognized in the handbooks, it has received only sporadic attention otherwise, and there is currently no adequate description or analysis of the phenomenon. In this paper, I provide the first detailed overview of the construction in the Attic dramatists (Aeschylus, Sophocles, Euripides and Aristophanes) and Herodotos, and argue that it marks polarity focus. I tentatively identify a diachronic source construction as well.