Dozens of dialects are spoken in Japan. The profusion is due to many factors, including the length of time the Japanese Archipelagohas been inhabited, its mountainous island terrain, and Japan’s long history of both external and internal isolation. Dialects typically differ in terms of pitch accent, inflectional morphology, vocabulary, and particle usage. Some even differ in vowel and consonantinventories, although this is uncommon.
The main distinction in Japanese accents is between Tokyo-type (東京式 Tōkyō-shiki) and Kyoto-Osaka-type (京阪式 Keihan-shiki). Within each type are several subdivisions. Kyoto-Osaka-type dialects are in the central region, roughly formed by Kansai, Shikoku, and western Hokuriku regions.
Dialects from peripheral regions, such as Tōhoku or Kagoshima, may be unintelligible to speakers from the other parts of the country. There are some language islands in mountain villages or isolated islands such as Hachijō-jima island whose dialects are descended from the Eastern dialect of Old Japanese. Dialects of the Kansai region are spoken or known by many Japanese, and Osaka dialect in particular is associated with comedy (see Kansai dialect). Dialects of Tōhoku and North Kantō are associated with typical farmers.
The Ryūkyūan languages, spoken in Okinawa and the Amami Islands (politically part of Kagoshima), are distinct enough to be considered a separate branch of the Japonic family; not only is each language unintelligible to Japanese speakers, but most are unintelligible to those who speak other Ryūkyūan languages. However, in contrast to linguists, many ordinary Japanese people tend to consider the Ryūkyūan languages as dialects of Japanese. This is the result of the official language policy of the Japanese government, which has declared these languages to be dialects and prohibited their use in schools.
The imperial court also seems to have spoken an unusual variant of the Japanese of the time. Most likely being the spoken form of Classical Japanese language, a writing style that was prevalent during the Heian period, but began decline during the late Meiji period.