Although there are some differences in the Korean language when you factor in the regional accents and dialects from the other regions such as Busan and Jeolla, the language spoken in Jeju Island is separate and distinct from the Korean language spoken in the mainland.
The Jeju dialect had been included by UNESCO in its Atlas of World's Endangered Languages in 2011. Jeju's Cultural Policy Division is fighting hard to preserve their language and had been holding the Jeju Language Contest every year.
Difference with Standard Korean
The distinct language, which is called Jejueo, is considered a dialect of Hangugeo, yet it is more than just a dialect. It could be regarded as a separate language because it cannot be understood by people from the mainland and has been in fact counted as a distinct language by UNESCO and the residents of Jeju-do. At the moment there are still about 5,000 to 10,000 fluent speakers of Jejueo but all of them were born before the year 1950.
Jejueo lacks the honorifics and formalities that are found in Standard Korean. For example, the formal greeting of "annyeonghaseyo" in Standard Korean is "ban-gapsuda" in Jejueo. The language also retains many words that are already considered archaic. It also has many words that have been borrowed from several foreign languages as well as words that were believed to have been used in Tamna, the ancient kingdom that once ruled the island.
Due to its isolation from the mainland, the island of Jeju had always been recognized for the uniqueness of its culture, which includes its indigenous language. The middle-aged folks of Jeju considered their language as the means to bond deeply with the other residents of the province. However, the number of native speakers is slowly diminishing and there are only very few fluent speakers or even users of the language among the younger generations. UNESCO reported that the intergenerational transmission of the language had been interrupted and the fluent speakers are already well into their 70s. The local government immediately acted on the declaration of UNESCO and campaigned aggressively to let people know of the imminent loss of the Jeju language and its value to the local residents of the island.
Still in danger of being lost
A director of the Cultural Policy Division of Jeju Province laments the fact that the loss of identity of the Jeju people contributes to the eventual loss of their unique language, projecting that in 30 to 50 years, Jejueo will disappear despite their efforts.
Still, they are doing everything they can to have the language preserved. Other preservation efforts are done by public and private organizations such as the Jejueo Preservation Corporation, the Tamna Cultural Festival that handles the annual Jeju Language contests, development of a smartphone app and after-school language learning programs.
The director of education of the province is in favor of reintroducing the language in the standard curriculum for public schools but they do not have a budget for it. In 2011 their budget for language preservation was 43 million won or about US$39,000, which was allocated for Internet broadcasting, teacher instruction and prizes for the annual speech contest.
Although there is no centralized effort from the national government, there are still many concerned groups that are helping to preserve Jejueo, such as University of Hawaii linguist William O’Grady, who proposed a collaboration blue print among several entities, including the Jeju Language Preservation Committee, UNESCO, the Smithsonian Institution, Jeju National University and the University of Hawaii. The plan called for written materials, Jejueo communities, administrators and teachers fluent in Jejueo. He cited the Hawaiian language as an example, which only had about 300 speakers at one time and now spoken by thousands due to concerted efforts.