The relevance and necessity of the study of this topic lies in the fact that, in comparison with other lexical groups, dialectal linguistic units are peripheral and can easily be lost. The purpose of this study was to thoroughly examine and analyse the emergence and development of dialects in different regions of Poland. The study employed structural-functional and dialectical methods, the method of synthesis, logical and comparative analysis, the method of generalisation, as well as comparative, statistical, and system analysis. As a result, it was found that linguists distinguish three urban dialects of Polish: Warsaw, Poznan, and Krakow. The Warsaw dialect is the most widespread urban Polish dialect. Over the past few decades, the Warsaw dialect has undergone considerable changes. These changes can be noticed on several levels: the mazurka has disappeared, the accent and intonation have been simplified, and some terms are pronounced differently. Simple past tense forms are used more often than complex ones, and the grammar generally becomes simpler. The number of English and Russian borrowings is growing. Conventional phrases and expressions are becoming less common, while slang and colloquial terms are becoming more common. Unfortunately, Polish urban dialects are under threat of extinction. Local libraries are crucial for the preservation of dialects, as they collect resources on urban dialects and hold events to promote their use. The study is practically important, since all the theoretical provisions, conclusions, and recommendations can be used by philologists to improve their knowledge of the dialectical vocabulary of Poland
