Evidence that Christ spoke Latin - he spoke in private with Pilate without an interpreter. It would have been highly unusual for Pilate to speak Hebrew or Aramaic. He also spoke directly to the Centurion with the sick boy, who would probably have known only Latin, since the Legions were then raised among the Italians only. He also spoke directly to the Greeks who came to see him near the end of his ministry, and preached in the Decapolis.
For St. Peter and St. Paul, we again see them speaking directly to members of the governing authority, such as Cornelius the Centurion, or Paul's missionary trip to Spain, as evidence they would have known Latin. Whether or not they had known it prior to Pentecost, when they received the gift of tongues, is an open question. Similarly, St. Thomas must have either learned or been gifted with the knowledge of Sanskrit, so that he could preach in India.