Kashubian (/kəˈʃuːbiən/) or Cassubian (/kəˈsuːbiən/; endonym: kaszëbsczi jãzëk; Polish: język kaszubski) is a West Slavic language[3] belonging to the Lechitic subgroup.

[8] The Kashubian language exists in two different forms: vernacular dialects used in rural areas, and literary variants used in education.

It first began to evolve separately in the period from the thirteenth to the fifteenth century as the Polish-Pomeranian linguistic area began to divide based around important linguistic developments centred in the western (Kashubian) part of the area.

[11] The Young Kashubian movement followed in 1912, led by author and doctor Aleksander Majkowski, who wrote for the paper Zrzësz Kaszëbskô as part of the Zrzëszincë group.

The earliest printed documents in Polish with Kashubian elements date from the end of the 16th century.

Many scholars and linguists debate whether Kashubian should be recognized as a Polish dialect or separate language.

However, experts caution that changes in census methodology and the socio-political climate may have influenced these results.

Kashubian literature has been translated into Czech, Polish, English, German, Belarusian, Slovene and Finnish.

Aleksander Majkowski and Alojzy Nagel belong to the most commonly translated Kashubian authors of the 20th century.

A considerable body of Christian literature has been translated into Kashubian, including the New Testament, much of it by Adam Ryszard Sikora (OFM).

Since 2005, Kashubian has enjoyed legal protection in Poland as an official regional language.

[35] An archaic word final stress is preserved in some two-syllable adjectives, adverbs, and regularly in the comparative degree of adverbs, in some infinitives and present and past tense forms, some nouns ending in -ô, in diminutives.

[39] The difference between southern and northern dialects dates as far back as the 14th—15th century and is the result of changes to the Proto-Slavic vowel length system.

[73] Kashubian, like other Slavic languages, has a rich system of derivational morphology, with prefixes, suffixes, deverbals, compounds, among others.

[74] [œ], [ø] (northern dialects) The following digraphs and trigraphs are used: Article 1 of the Universal Declaration of Human Rights in Kashubian: Article 1 of the Universal Declaration of Human Rights in English:[75]