Prepositional usage in spatial constructions in the Slavic languages is frequently unpredictable and perplexing to the non-native speaker. This is especially true in the case of the preposition na. By examining categories of spatial phenomena with which the preposition na is used, it is possible to better understand why na is used in many circumstances. This not only has implications for language pedagogy, but promises to aid the understanding of certain aspects of diachronic change in the semantics of the prepositional systems of the Slavic languages.