Ξανθίας
φέρε νυν κατείπω τοῖς θεαταῖς τὸν λόγον,
ὀλίγ᾽ ἄτθ᾽ ὑπειπὼν πρῶτον αὐτοῖσιν ταδί,
μηδὲν παρ᾽ ἡμῶν προσδοκᾶν λίαν μέγα,
I think προσδοκαν is an infinitive here (‘to expect nothing…’) but I’m not sure. Perseus says it could also be the imperfect 3rd pl but I don’t think this would work. Can anyone help?
You’re right and Perseus is wrong. It’s an infinitive.
3rd plural imperfect would have augment, the contracted vowel would be ω (contracted from α+ο), and the word would be paroxytone (acute accent on penult): προσεδὀκων. Not only that, but as you recognize, 3rd plural imperfect wouldn’t make sense here.
The Perseus “word-study tool” is very inaccurate. Never rely on it. In fact, never use it.