Brian Friel once described his “Translations” as having “to do with language and only language” — a subject that the great Irish playwright mastered not only as a writer but as a thinker, an explorer of how we communicate or fail to do so. Offhand, I certainly cannot think of a play that confronts these matters more movingly than this 1980 piece, set in 1833 in a small community in County Donegal, where the townspeople, like millions in their country at the time, spoke primarily in Irish, or Gaelic.