Micronesian languages, group of mutually unintelligible languages belonging to the Eastern, or Oceanic, branch of the Austronesian (Malayo-Polynesian) language family and most closely related to the Melanesian and Polynesian languages. The seven languages in the Micronesian group, all closely related, are the Nuclear Micronesian languages, including Marshallese, Gilbertese, Chuukese, Pohnpeian, Kosraean, Carolinean, and Ulithian. Two more languages of Micronesia that belong to the Polynesian group are Nukuoro and Kapingamarangi. Two languages spoken in Micronesia appear to be most closely related to the Western, or Indonesian, branch of the Austronesian languages—Chamorro, closely similar to the languages of the Philippines, and Palauan, the affinities of which are less certain but clearly Indonesian.
In addition, two Micronesian languages, Yapese and Nauruan, are of uncertain relation to the Nuclear Micronesian group. Nuclear Micronesian languages are similar in phonology and close enough in structure to show their close interrelationship, but vocabulary items generally show few similarities, with less than 25 percent of the total vocabulary similar within closely related languages.