Sioux is a Siouan language spoken by over 30,000 Sioux in the United States and Canada, making it the fifth most spoken indigenous language in the United States or Canada, behind Navajo, Cree, Inuit languages, and Ojibwe. Since 2019, "the language of the Great Sioux Nation, three dialects, Dakota, Lakota, and Nakota" is the official indigenous language of South Dakota. Regional variation Sioux has three major regional varieties, with other sub-varieties: Lakota ( Lakȟóta, Teton, Teton Sioux) Western Dakota (a.k.a. Yankton-Yanktonai or Dakȟóta, and erroneously classified, for a very long time, as "Nakota") Yankton (Iháŋktȟuŋwaŋ) Yanktonai (Iháŋktȟuŋwaŋna) Eastern Dakota (a.k.a. Santee-Sisseton or Dakhóta) Santee (Isáŋyáthi: Bdewákhathuŋwaŋ, Waȟpékhute) Sisseton (Sisíthuŋwaŋ, Waȟpéthuŋwaŋ) Yankton-Yanktonai (Western Dakota) stands between Santee-Sisseton (Eastern Dakota) and Lakota within the dialect continuum. It is phonetically closer to Santee-Sisseton but lexically and grammatically, it is much closer to Lakota. For this reason Lakota and Western Dakota are much more mutually intelligible than each is with Eastern Dakota. The assumed extent of mutual intelligibility is usually overestimated by speakers of the language. While Lakota and Yankton-Yanktonai speakers understand each other to a great extent, they each find it difficult to follow Santee-Sisseton speakers. Closely related to the Sioux language are the Assiniboine and Stoney languages, whose speakers use the self-designation term (autonym) Nakhóta or Nakhóda. Comparison of Sioux and Nakota languages and dialects Phonetic differences The following table shows some of the main phonetic differences between the regional varieties of the Sioux language. The table also provides comparison with the two closely related Nakota languages (Assiniboine and Stoney). Lexical differences Writing systems In 1827, John Marsh and his wife, Marguerite (who was half Sioux), wrote the first dictionary of the Sioux language. They also wrote a "Grammar of the Sioux Language." Life for the Dakota changed significantly in the nineteenth century as the early years brought increased contact with white settlers, particularly Christian missionaries. The goal of the missionaries was to introduce the Dakota to Christian beliefs. To achieve this, the missions began to transcribe the Dakota language. In 1836, brothers Samuel and Gideon Pond, Rev. Stephen Return Riggs, and Dr. Thomas Williamson set out to begin translating hymns and Bible stories into Dakota. By 1852, Riggs and Williamson had completed a Dakota Grammar and Dictionary (Saskatchewan Indian Cultural Center). Eventually, the entire Bible was translated. Today, it is possible to find a variety of texts in Dakota. Traditional stories