OK, won't close this note before. But to be honest, this kind of question is not what map notes were meant for. You have a tagging question and these are better asked in the community forum (e.g. https://community.openstreetmap.org/c/general/tagging/70). 

While the OSM Wiki (https://wiki.openstreetmap.org/wiki/Key:language:*) is vague about using it for something else than languages taught at a language school, it does hints that tagging the place with language:en=yes could be a solution to your problem. I'm not familiar with any more specific way to indicate languages an amenity offers services in.