in the Czech Republic. It is mainly used by the Polish minority, but also by some people of Czech and Slovak ethnicity in the same area. The Czech government considers the Cieszyn Silesian dialect to be a variety of Polish, and Polish is a recognised minority language in the Karviná and Frýdek-Místek Districts, where the dialect is natively spoken. In Poland, because of the closer linguistic relationship between the dialect and standard Polish, the dialect is becoming diluted more quickly than in the Czech Republic. Mutual intelligibility Grammatically and phonologically, the Cieszyn Silesian dialect is closer to Polish than to Czech. Czechs who are not familiar with the dialect may therefore have considerable difficulty understanding it. The mutual intelligibility with other dialects of Polish is generally higher. Classification Cieszyn Silesian is a transitional dialect, located roughly at the mid-point of a dialect continuum connecting Czech, Slovak, and Polish. Polish linguists tend to classify it as a Silesian Polish dialect, and thus maintain that the territory of Polish extends into Czech Silesia. This interpretation emphasizes the history of the dialect over the current situation, as it has its roots mainly in Polish. The other view, which is generally favoured by Czech and Slovak linguists, emphasizes a more recent distinction between the dialect spoken on the Polish side of the border from the dialect on the Czech side, with the latter considered to have become a "mixed Czech-Polish dialect" (). Since the border dividing Cieszyn Silesia was created in 1920, there has been increased language contact with Czech, in particular the neighbouring Lachian dialects and, more recently, Common Czech. In the early 19th century Jerzy Samuel Bandtkie was the first Polish researcher (of German descent) trying to argue in the spirit of the Age of Enlightenment that Silesian has Polish and not Czech roots. In his dissertation Wiadomości o języku polskim w Szląsku i o polskich Szlązakach Bandtkie [wrongly] placed the border of Polish along the Ostravice River. A two-volume survey of the dialect on the Czech side of the border was undertaken by Adolf Kellner in the 1940s, which named it "Eastern Lachian" (), thus grouping it together with the Lachian dialects. This was a politically motivated decision, however, as the Nazi censors would have forbidden publication of any title that linked Slavic languages to the recently annexed Cieszyn region. The earliest linguistically scientific modern subdivision of the Silesian dialects in