A term to describe the difficulty of dealing with people with whom you do not share a common language. It's perhaps best illustrated with some contextual examples:

"As an ESL teacher in South Korea, I find it difficult to make friends, because of the language barrier."

"The language barrier makes it easy to mistakenly believe people from other cultures to be rude, stupid, or both."

"Practicing your charades skills and carrying around a pencil and sketch pad are both good ways of getting around the language barrier."