Adam Clarke on Acts 21:37

Canst thou speak Greek? - Claudius Lysias was not a Roman; he had, as himself informs us, purchased his citizenship of Rome with a great sum of money; (see Act 22:28); and it is very likely that he was but imperfectly acquainted with the Latin tongue; and the tumult that was now made, and the discordant noise, prevented him from clearly apprehending what was said; and, as he wished to know the merit of the cause, he accosted Paul with, ἙλληνιϚι γινωσκεις, Dost thou understand Greek? And when he found that he did understand it, he proceeded to question him as below.