Ryukyuan languages
As the Japanese (or Yamato people) learned to write and read a thousand years before the Ryukyuans and absorbed many Chinese language forms, the early literature which records the language of the Old Japanese imperial court show archaisms which are closer to Okinawan dialects. The Ryukyuan language is divided into two main groups, Northern Ryukyuan languages and Southern Ryukyuan languages, and generally are considered the existence of five Ryukyuan languages; Amami, Okinawa, Miyako, Yaeyama and Yonaguni, while the sixth Kunigami is added due to diversity. Within them and on specific islands exist local dialects, of which many vanished. Despite the use of Shuri Okinawan in the Shuri Court and its reputation, there's no standard variety. Thus, the Ryukyuan languages constitute a cluster of local dialects termed as unroofed abstand languages, "unroofed" meaning without written standard.