Macro-Siouan languages
In the 19th century, Robert Latham suggested that the Siouan languages are related to the Caddoan and Iroquoian languages. In 1931, Louis Allen presented the first list of systematic correspondences between a set of 25 lexical items in Siouan and Iroquoian. In the 1960s and 1970s, Wallace Chafe further explored the link between Siouan and Caddoan languages. In the 1990s, Marianne Mithun compared the morphology and syntax of all the three families. At present, the Macro-Siouan hypothesis based on relations among Siouan, Caddoan, and Iroquoian is not universally accepted as proven.
Samoan language
Samoan is an analytic, isolating language and a member of the Austronesian family, and more specifically the Samoic branch of the Polynesian subphylum. It is closely related to other Polynesian languages with many shared cognate words such as "aliʻi", "ʻava", "atua", "tapu" and numerals as well as in the name of gods in mythology.