J.R.R. Tolkien called his invented language modeled largely on Finnish Quenya.
Quenya is one of the major Elvish languages in Tolkien’s mythology. Its sound and grammatical structure were strongly influenced by Finnish, while its vocabulary and history were developed as part of Tolkien’s broader legendarium.
Tolkien also drew inspiration from Latin and Greek, among other languages. In his fictional history, Quenya was associated especially with the High Elves and functioned as a formal or ancient language in many settings.
Quenya is often confused with Sindarin, another major Elvish language. Sindarin was more commonly spoken by Elves in Middle-earth during the events of The Lord of the Rings, whereas Quenya had an older, more ceremonial status.