Elvish
Elvish is the language spoken and shared by those of Fey descent, including Eladrin and Elves. Just as Elves are likely descendants of they fey cousins the Eldarin, Elvish is likely a language descended from that still spoken in the Feywild: Sylvan.
Elvish is fluid, with subtle intonations and intricate grammar. Elven literature is rich and varied, and their songs and poems are famous among other races. Many bards learn their language so they can add Elvish ballads to their repertoires.