Quenya is the Elvish language created by J.R.R. Tolkien that is based largely on Finnish.
Tolkien developed Quenya as one of the major languages of his legendarium. Its sound and grammatical structure were strongly influenced by Finnish, a language he admired, although Quenya is not Finnish and has its own vocabulary, history, and internal development.
Within the mythology, Quenya is associated especially with the High Elves and with the ancient Elven traditions of Valinor. It is often presented as a formal or literary language rather than the everyday speech of all Elves in later Middle-earth.
Sindarin is another major Elvish language, but Tolkien based much of its sound and structure on Welsh. Adûnaic is associated with the Númenóreans, while Khuzdul is the secret language of the Dwarves. These distinctions make the languages easier to separate.