Sindarin is the fictional language spoken by many Elves of Beleriand in Tolkien’s legendarium.
Tolkien based much of Sindarin’s sound and structure on Welsh, one of his favorite real-world languages. In the internal history of Middle-earth, Sindarin developed from an earlier Elvish language after the Sindar remained in Middle-earth while many other Elves traveled to Aman. It became the common Elvish language of much of Beleriand during the First Age.
Sindarin is distinct from Quenya, another major Elvish language. Quenya was associated especially with the High Elves and was influenced by Finnish, while Sindarin served a broader everyday role among Elves in Middle-earth. Tolkien’s linguistic design included sound changes and historical relationships rather than just lists of invented words.
The language appears in names such as Galadriel, meaning “Lady of the Light,” and Minas Tirith, meaning “Tower of Guard.” Tolkien’s published works contain only part of the language’s full grammatical system.