Beginning with the early postwar years, Polish has been the language of all but a very few citizens. Grouped with Czech and Slovak in the West Slavic subgroup of the Slavonic linguistic family, Polish uses a Latin alphabet because the Roman Catholic Church has been dominant in Poland since the tenth century (see The Origins of Poland , ch. 1). Documents written in Polish survive from the fourteenth century however, the literary language largely developed during the sixteenth century in response to Western religious and humanistic ideas and the availability of printed materials. In the eighteenth century, the Enlightenment stimulated a second period of advances in the literary language. When the Polish state fell at the end of the eighteenth century, the language played an important role in maintaining the Polish national identity (see The Three Partitions, 1764-95 , ch. 1).

Although modern Polish was homogenized by widespread education, distribution of literature, and the flourishing of the mass media, several dialects originating in tribal settlement patterns survived this process in the late twentieth century. Among the most significant are Greater Polish and Lesser Polish (upon a combination of which the literary language was formed), Silesian, Mazovian, and Kashubian, which is sometimes classified as a separate language.

Data as of October 1992