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).

"[9][10] Life for the Dakota changed significantly in the nineteenth century as the early years brought increased contact with European settlers, particularly Christian missionaries.

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).

Around the same time, missionaries in other Dakota bands were developing their own versions of the written language.

Prior to the introduction of the Latin alphabet, the Dakota did have a writing system of their own: one of representational pictographs.

Palmer writes that, As a written language, it [pictographs] was practical enough that it allowed the Lakota to keep a record of years in their winter counts which can still be understood today, and it was in such common usage that pictographs were recognized and accepted by census officials in the 1880s, who would receive boards or hides adorned with the head of the household’s name depicted graphically.

34)[full citation needed]For the missionaries, however, documenting the Bible through pictographs was impractical and presented significant challenges.

For example, the suffix –pi is added to the verb to mark the plurality of an animate subject.