Asia is home to hundreds of languages comprising several families and some unrelated isolates. The most spoken language families on the continent include Austroasiatic, Austronesian, Japonic, Dravidian, Indo-European, Afroasiatic, Turkic, Sino-Tibetan, Kra–Dai and Koreanic. Many languages of Asia, such as Chinese, Persian, Sanskrit, Arabic or Tamil have a long history as a written language.