I find it absolutely interesting that people in the past would discover new lands or be visited by people from countries never heard of and be able to communicate with each other. While I understand hand gestures and body language can be used to communicate, the interpretation changes from culture to culture which makes me believe it couldn't have been very effective or efficient.

And a follow up, how did people learn the foreign language (both spoken and written language) and become translators?

PS: I mentioned the time period because I was reading about the Age of Exploration but the question is also applicable to other time periods and from non-European sources.

Thanks in advance!

Edit: grammar