language barrier
Refers to the difficulty in communication caused by differences in language. Often used in contexts of travel, international relations, or cross-cultural communication.
When traveling abroad, you often run into a language barrier.
I studied a foreign language hard to overcome the language barrier.
Compound of 言葉 (kotoba, 'language') + の (no, possessive particle) + 壁 (kabe, 'wall'). The metaphorical use of 壁 for a barrier is common in Japanese.