Quenya was the Tolkien language primarily based on Finnish.
Tolkien developed Quenya as an elegant language associated especially with the High Elves. Its sounds and grammar were influenced strongly by Finnish, while its vocabulary and history were created within Tolkien’s own linguistic system. Quenya appears in names, poems, songs, and formal speech throughout the legendarium.
Quenya is sometimes confused with Sindarin, another major Elvish language. Sindarin was more commonly spoken by Elves in Middle-earth and drew much of its linguistic inspiration from Welsh. Tolkien did not merely invent isolated words; he constructed related languages with historical changes, dialects, and imagined speakers, treating language development as part of the history of Middle-earth.