Jejueo, in Korean 제주어 (Je-ju-eo), is a Koreanic language spoken mainly in Jeju Island (33°22'N 126°32'E), South Korea. It is also used by some ethnic Koreans in the Osaka area of Japan, who fled there in the late 1940s and early 1950s at a time of harsh military oppression on Jeju Island (ELP).
In 2010, UNESCO classified it as a "critically endangered" language.
Between 5'000 and 10'000 speak the language in a population of around 100'000 people. Moreover, most of its fluent speakers are aged over 75 and its transmission is declining (ELP).
Some consider it as a variation of standard Korean. However, nowadays, most people agree it is a language in itself, that belongs to the Koreanic languages (Campbell 2018).
You can get introduced toJejueo with the help of a Jeju lady in the video below.
In this video, two staff from Talk To Me In Korean, try to see if they can understand some simple phrases in Jejueo.