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.
Cebuano language
The Cebuano () or Cebuan language ( ), also often referred informally to by most of its speakers simply as Bisaya (English translation: "Visayan", not to be confused with other Visayan languages), is an Austronesian language spoken in the Philippines by about closely 45 million people in Central Visayas, western parts of Eastern Visayas and most parts of Mindanao, most of whom belong to various Visayan ethnolinguistic groups, mainly the Cebuanos. While Filipino (Tagalog) has the most number of speakers of Philippine languages, Cebuano had the largest native language-speaking population in the Philippines until about the 1980s. It is by far the most widely spoken of the Visayan languages, which are in turn part of the wider Philippine languages.