Hernan Cortes and other conquistadors made alliances with the native tribes of Mesoamerica, the Tlaxcalans in particular. Presumably this required more than rudimentary communication.

I suppose the real question is, how do two people who speak two different languages with no common roots communicate with each other?

I understand that later there would have been interpreters that knew both languages, but what about the very first, initial communication between Europeans and Mesoamericans?

Thanks in advance for your response.