The Ryukyuan languages comprise a sister branch to the Japanese dialects and Standard Japanese within the Japonic Language family. A UNESCO report has identified six distinct languages within the Ryukyuan branch, but there is high dialectal diversity even within many of these purported languages. They can be characterized as dialect continua, and although they share a number of grammatical and lexical features, they are not mutually intelligible with each other or with the many dialects of mainland Japan. Yaeyaman is one of the three languages that make up the Southern Ryukyan sub-branch, along with Miyakoan and Yonaguni. All Ryukyuan languages are in some state of endangerment, and their survival into future generations is highly threatened.