Ancient Tongue

At the end of the Great Journey, the Eldar became separated. The Noldor and the Vanyar were transported across the Great Sea into the West, and they were later joined by many of the Teleri, though many others of that people remained behind in Middle-earth.

In Aman the ancient Elvish tongue was preserved as Quenya, especially among the Noldor and the Vanyar, but the changefulness of Middle-earth meant that the tongues of the Elves there evolved into different forms. Principal among these was Sindarin, the language of the Grey-elves of Beleriand.

When the Noldor returned to Middle-earth, they found that the people they had left there long ages earlier were now speaking a different language: one that was recognisable in many ways, but clearly distinct from their own ancient Quenya. Through the edict of King Thingol of the Sindar, the High-elven tongue fell out of common use in Middle-earth, and so the Elvish usually used east of the Sea was Sindarin. Nonetheless knowledge of the Ancient Tongue was preserved, and it was still spoken by the High Elves (and by scholars of their languages) even at the end of the Third Age.