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.
Tuvalu
The Tuvaluan language and English are the national languages of Tuvalu. Tuvaluan is of the Ellicean group of Polynesian languages, distantly related to all other Polynesian languages such as Hawaiian, Māori, Tahitian, Rapa Nui, Samoan and Tongan. It is most closely related to the languages spoken on the Polynesian outliers in Micronesia and northern and central Melanesia. The Tuvaluan language has borrowed from the Samoan language, as a consequence of Christian missionaries in the late 19th and early 20th centuries being predominantly Samoan.