Are Polish “DLA” and “KU” really synonymic purposive prepositions?

Abstract “Dla” and “ku” are widely considered to be multifunctional and polysemous prepositions sharing at least some semantic components. While agreeing with their wide functional spectrum, the author argues for them to be monosemous: “dla” brings a positive evaluation of something from a given perspective, whereas “ku” points to something happening when something else occurs. By analysing their connectivity and interchangeability, the author proves that, against lexicographic descriptions, the semantic structures of these prepositions are not identical and, in fact, do not share any semantic components. The semantic differences between the two prepositions make them prone to different types of contexts. “Dla” appears in purposive-intentional and benefactive contexts and collocates with various types of nouns, from gerunds to personal nouns. “Ku” prefers resultative sentences, in which it introduces a special stylistic tone of sobriety. Due to this, possible collocations of this preposition are very limited, and many are reported to be undergoing lexicalization.