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.
Siraya language
The Siraya language entered the historical record in the early 17th century when traders from the Dutch East India Company, expelled from mainland China and Chinese waters, set up a stronghold on Taiwan at Fort Zeelandia, which was in the Siraya-speaking area. During the period of Dutch rule in Taiwan, Calvinist missionaries used Siraya and Babuza (also known as "Favorlang") as contact languages. A translation of the Gospel of St. Matthew into Siraya (174 pages of Siraya and Dutch text, Gravius 1661) and a catechism in Siraya (288 pages of Siraya and Dutch text, Gravius 1662) were published, and have been subsequently republished. The Dutch colony was driven out in 1661 by Ming loyalist refugees from China, and Taiwan was subsequently incorporated into the Qing Empire. During the period of Qing Dynasty rule, use of Siraya receded, but some Siraya language materials survive in the form of Siraya land contracts with Chinese translations, known as the Sinckan Manuscripts. The last records were lists of words made in the early 19th century.