The small group of , natively called , depending on classification, either are the most divergent form of Japanese, or comprise a branch of Japonic (alongside mainland Japanese, Northern Ryukyuan, and Southern Ryukyuan). Hachijō is currently spoken on two of the Izu Islands south of Tokyo (Hachijō-jima and the smaller Aogashima) as well as on the Daitō Islands of Okinawa Prefecture, which were settled from Hachijō-jima in the Meiji period. It was also previously spoken on the island of Hachijō-kojima, which is now abandoned. Based on the criterion of mutual intelligibility, Hachijō may be considered a distinct Japonic language, rather than a dialect of Japanese.
Hachijō is a descendant of Eastern Old Japanese, retaining several unique grammatical and phonetic features recorded in the Azuma-dialect poems of the 8th-century Man'yōshū and the Fudoki of Hitachi Province. Hachijō also has lexical similarities with the dialects of Kyushu and even the Ryukyuan languages; it is not clear if these indicate that the southern Izu islands were settled from that region, if they are loans brought by sailors traveling among the southern islands, or if they might be independent retentions from Old Japanese.
Hachijō is a moribund language with a small and dwindling population of primarily elderly speakers. Since at least 2009, the town of Hachijō has supported efforts to educate its younger generations about the language through primary school classes, karuta games, and Hachijō-language theater productions. Nevertheless, native speakers are estimated to number in the "low hundreds," and younger generations are not learning or using the language at home.
Classification and dialects
The Izu Islands dialects of Hachijō are classified into eight groups according to the various historical villages within Hachijō Subprefecture. On Hachijō-jima, these are Ōkagō, Mitsune, Nakanogō, Kashitate, and Sueyoshi; on Hachijō-kojima, these were Utsuki and Toriuchi; and the village of Aogashima is its own group. The dialects of Ōkagō and Mitsune are very similar, as are those of Nakanogō and Kashitate, while the Aogashima and Sueyoshi dialects are distinct from these two groups. The Utsuki and Toriuchi dialects have not been subcategorized within Hachijō, though the Toriuchi dialect has been noted to be very similar to the Ōkagō dialect in phonology. The dialect(s) of the Daitō Islands also remain uncategorized.
The Hachijō language and its dialects are classified by John Kupchik and the National Institute for Japanese Language and Linguistics (NINJAL), respectively, within the Japonic family as follows:
Proto-Japonic
Proto-Japanese
Eastern Old Japanese
Hachijō language
Ōkagō & Mitsune dialects (Downhill dialects) Nakanogō & Kashitate dialects (Uphill dialects) Sueyoshi dialect Aogashima dialect Central Old Japanese (including Western Old Japanese) Japanese language Proto-Ryukyuan Ryukyuan languages
The dialects of Aogashima and Utsuki are quite distinct from the other varieties (and each other). The Aogashima dialect exhibits slight grammatical differences from other varieties, as well as noticeable lexical differences. The Utsuki dialect, on the other hand, is lexically similar to the Toriuchi dialect and those of Hachijō-jima, but has undergone several unique sound shifts such as the elimination of the phonemes and ; the loss of the latter is referred to as being sitagirecjaQcja "cut-tongued" by those of other villages, or citagije in Utsuki.
The dialects of Hachijō-jima are, like its villages, often referred as being or . The villages of Ōkagō and Mitsune in the northwest are Downhill, while the villages of Nakanogō, Kashitate, and Sueyoshi in the south are Uphill—though the Sueyoshi dialect is not particularly close to those of the other "Uphill" villages. Therefore, the Sueyoshi dialect is often excluded from the term "Uphill dialects."
As the number of remaining speakers of Hachijō as a whole is unknown, the numbers of remaining speakers of each dialect are also unknown. Since the abandonment of Hachijō-kojima in 1969, some speakers of the Utsuki and Toriuchi dialects have moved to Hachijō-jima and continue to speak the Hachijō language, though their speech seems to have converged with that of the Downhill dialects. As late as 2009, the Toriuchi dialect had at least one remaining speaker, while the Utsuki dialect had at least five.