The title pretty much explains it. I realize why Latine was chosen by this forum and in other places (as in lingua Latina or even just lingua Latina is rather long) but has anyone ever seen that usage in print, whether classical or otherwise? It just seems more intuitive than "in <language>" as it is done in, say, English; prepositional phrases being used as adverbs just seem silly to me. (There are other prepositional phrases used as adverbs in English that I don't linguistically understand either.)