Answer: Tibetan and Kalmyk Oirat
To the ears of native English speakers with no other language instruction, the high pitched language spoken by the Ewoks in the Star Wars universe sounds like mere gibberish. For many Star Wars viewers around the world, however, it was possible to pick up bits of actual conversation in the chattering of the diminutive tree-dwellers.
The Ewok language was created by Return of the Jedi sound designer Ben Burtt by crafting a pseudo-pidgin language based primarily on Tibetan (the language of the Tibet Autonomous Region of the People’s Republic of China) and Kalmyk Oirat (the language of the Kalmyk people, a group of Mongolian descendants found today in the Republic of Kalmykia on the western shore of the Caspian Sea). Burtt used recordings of native speakers of these languages as a basis for sounds that became the Ewok language and were performed by voice actors who imitated the native speakers’ voices in different styles to create the distinctive Ewok chatter. For the scene in which C-3PO speaks Ewokese, actor Anthony Daniels worked with Burtt and invented words based on the recordings.
Unlike many other sci-fi and fantasy languages, such as Klingon, there’s no way to directly translate Ewok as no attempt was ever made to match up the created dialogue with actual scripted English. As such, any bit of dialogue someone might pick up has no bearing on what is actually happening on screen. Listeners might hear bits of casual conversation, Tibetan prayers, and other common elements of daily speech from the languages used to create Ewokese.