Austronesian linguist K. Alexander Adelaar classified Sasak as one of the Malayo-Sumbawan languages group (a group he first identified) of the western Malayo-Polynesian family in a 2005 paper. Sasak's closest sister language is Sumbawa and, with Balinese, they form the Balinese-Sasak-Sumbawa (BSS) subgroup. BSS, Malayic (which includes Malay, Indonesian and Minangkabau) and Chamic (which includes Acehnese) form one branch of the Malayo-Sumbawan group. The two other branches are Sundanese and Madurese. This classification puts Javanese, previously thought to belong to the same group, outside the Malayo-Sumbawan group in a different branch of the western Malayo-Polynesian family.