Japanese (日本語 "Nihon-go" in Japanese) is the official language of Japan, in East Asia. Japanese belongs to the Japonic language family, which also includes the endangered Ryukyuan languages. One theory says Japanese and Korean are related, but most linguists no longer think so. Other theories about the origin of Japanese are that it related to the Austronesian languages, the Dravidian languages, or the controversial Altaic language family. Interestingly, a different term is used for Japanese as a course of study by citizens: it is "kokugo" (国語), which means national language. Nonetheless, Japanese is still referred to as 日本語 by the Japanese.