Almost all known words and phrases come from the Vocabula Mahakuassica, a vocabulary written by the Swedish missionary Johannes Campanius in New Sweden during the 1640s and published by his grandson Thomas Campanius Holm in two separate works in 1696[1] and 1702.

[2] Peter Stephen Du Ponceau translated the 1702 work from Swedish to English in 1834.

[4] Linguist Marianne Mithun believes this limited data is sufficient to classify Susquehannock as a Northern Iroquoian language, closely related to the languages of the Haudenosaunee Confederacy.

[5] Examples of Susquehannock-language place names include Conestoga, Juniata, and Swatara.

Indian Villages and Place Names in Pennsylvania with Numerous Historical Notes and References (1928), a book by Dr. George P. Donehoo identifies place names derived from the Conestoga language.