Sindarin is the Tolkien-created Elvish language associated especially with the Elves of Beleriand.
In Tolkien’s linguistic history, Sindarin developed from an earlier Elvish language spoken by the Sindar, or Grey Elves. It became the everyday Elvish language of many Elves in Middle-earth during the First and Second Ages and remained widely used in the Third Age.
Quenya, another major Elvish language, had a more formal and historical status among many speakers. Tolkien modeled aspects of Sindarin’s sound on Welsh, while Quenya drew strongly on Finnish phonology and grammar. These influences helped Tolkien build languages with distinct histories rather than treating “Elvish” as one uniform tongue.
Names such as Galadriel, Celeborn, and Moria are connected with Tolkien’s invented linguistic traditions, although individual names can have complex histories. Sindarin should not be confused with the Black Speech of Mordor or Khuzdul, the secret language of the Dwarves.