Some of the people they encountered didn't have them (e.g. the Diagnosan) and Sikozu had to learn Crichton's language from listening to him (I assume she also had to learn Nebari and Luxan etc) but of course she was an incredibly fast learner. At least they provided an explanation, even if it was very babel-fish; most series don't give them and BSG drives me crazy by being a parallel-developed US society (but I love it anyway).