In the end of the 13th Century the Premyslids had united the Polish and Bohemian thrones, in OTL Poland lost Silesia when it separated from Bohemia, what if the union between Poland and Bohemia was as permanent as the Polish-Lithuanian Commonwealth, during that time, the literary language of Poland was Czech in OTL the Poles living in the Duchy of Wroclaw aka Lower Silesia and PLC shed the Czech influence when Polish became a known literary language and Printing in Polish started, Opole-Raciborz, the Czech influence wore off later due to cultural divergence between the Poles and Czechs, what if Poland and Bohemia's union remains and sticks until the age of Nationalisms - it would mean that the Poles would speak Czech as their second language, how would that effect the development of Polish language?