In episodes 4-6 3-P0 claimed he knew 6 million forms of communication. Then we find out in episode 1 that Anakin built 3-P0. I doubt that Anakin as a child or adult knew how to speak 6 million languages. 3-P0's been with the republic, the rebels, and in some cases (according to the comics) the empire. Even still I doubt that with his knew owners he learned 6 million languages. It's very doubtful.