The phrase προσέχουσ' ἔτυχον presents a notable syntactic feature where the aorist of τυγχάνω ('to happen', 'to meet') governs a present participle (προσέχουσ' from προσέχω). While τυγχάνω often takes an infinitive or accusative with infinitive, the construction with a participle, particularly one indicating an attendant circumstance or simultaneous action ('happening to be paying attention'), is less common and requires attention to the aspectual interplay: the present participle emphasizes the ongoing nature of the action at the moment of the 'chance' encounter, rather than the action itself being the object of the chance. This specific usage highlights the colloquial, dramatic rhythm of Aristophanic dialogue, where the syntax mirrors the immediacy of the character's realization.