Simple speech (Ukrainian: проста мова, romanized: prosta mova; Polish: mowa prosta; Belarusian: простая мова, romanized: prostaya mova), also translated as simple language or simple talk, is an informal reference to various uncodified vernacular forms of Ukrainian and Belarusian in the areas historically influenced by Polish culture.
This term has been commonly used, e.g., as a reply to the question about the mother tongue or language spoken at home by the Tutejszy in the historical region of Kresy, which covers parts of modern Ukraine, Belarus, Lithuania and a bit of Latvia.
[5] The term "simple" refers to the speech of "simple people", as a distinction to the "high style" of official and written language of the time and region: Church Slavonic in the case of Old Ukrainian of 16th–17th centuries[2] and the Grand Duchy of Lithuania,[4] and the Polish language in the case of Kresy.
[1] Polish linguist Mirosław Jankowiak reported in 2015 that most people in rural areas of Vilnius Region who declare themselves as Poles speak Polish-Belarusian "simple speech".
[1] Jankowiak also notes that Bronisław Taraszkiewicz who was first to codify the Belarusian language (1918, "Taraškievica") hailed from Mačiuliškės of Vilnius region, and it appears that his version of Belarusian was influenced by the "simple speech" native to him.