Wikipedia
Quenya is a fictional language devised by J. R. R. Tolkien and used by the Elves in his legendarium.
Tolkien began devising the language around 1910 and restructured the grammar several times until Quenya reached its final state. The vocabulary remained relatively stable throughout the creation process. Also, the name of the language was repeatedly changed by Tolkien from Elfin and Qenya to the eventual Quenya. The Finnish language had been a major source of inspiration, but Tolkien was also familiar with Latin, Greek, and ancient Germanic languages when he began constructing Quenya. Another notable feature of Tolkien's Elvish languages was his development of a complex internal history of characters to speak those tongues in their own fictional universe. He felt that his languages changed and developed over time, as with the historical languages which he studied professionally—not in a vacuum, but as a result of the migrations and interactions of the peoples who spoke them.
Within Tolkien's legendarium, Quenya is one of the many Elvish languages spoken by the immortal Elves, called Quendi ('speakers') in Quenya. Quenya translates as simply "language" or, in contrast to other tongues that the Elves met later in their long history, "elf-language". After the Elves divided, Quenya originated as the speech of two clans of "High Elves" or Eldar, the Noldor and the Vanyar, who left Middle-earth to live in Eldamar ("Elvenhome"), in Valinor, the land of the immortal and God-like Valar. Of these two groups of Elves, the Noldor returned to Middle-earth where they met the Sindarin-speaking Grey-elves. The Noldor eventually adopted Sindarin and used Quenya primarily as a ritual or poetic language, whereas the Vanyar who stayed behind in Eldamar retained the use of Quenya. In this way, the Quenya language was symbolic of the high status of the Elves, the firstborn of the races of Middle-earth, because of their close connection to Valinor, and its decreasing use also became symbolic for the slowly declining Elven culture in Middle-earth. In the Second Age of Middle-earth's chronology the Men of Númenor learnt the Quenya tongue. In the Third Age, the time of the setting of The Lord of the Rings, Quenya was learnt as a second language by all Elves of Noldorin origin, and it continued to be used in spoken and written form, but their mother-tongue was the Sindarin of the Grey-elves. As the Noldor remained in Middle-earth, their Noldorin dialect of Quenya also gradually diverged from the Vanyarin dialect spoken in Valinor, undergoing both sound changes and grammatical changes.
The language featured prominently in Tolkien's The Lord of the Rings trilogy, as well as in his posthumously published history of Middle-earth The Silmarillion. The longest text in Quenya published by Tolkien during his lifetime is the poem " Namárië", and other published texts are generally no longer than a few sentences. At his death, Tolkien left behind a number of unpublished writings on Quenya, and later Tolkien scholars have prepared his notes and unpublished manuscripts for publication in the journals Parma Eldalamberon and Vinyar Tengwar, also publishing scholarly and linguistic analyses of the language. Tolkien never created enough vocabulary to make it possible to converse in Quenya, although fans have been writing poetry and prose in Quenya since the 1970s. This has required conjecture and the need to devise new words, in effect developing a kind of neo-Quenya language.