The goal of our study is to establish the usage patterns of the Ukrainian partitive genitive and accusative objects based on a corpus of modern Ukrainian (ukTenTen 2020). This article focuses on differences between concrete and abstract mass nouns as objects of perfective-imperfective verb pairs. Our corpus study targets relations between the grammatical aspect of verbs, Aktionsart prefixes and the partitive genitive, which has been traditionally associated with perfectivity. We found that Ukrainian imperfective verbs occur regularly with partitive genitive objects, and that aspect does not influence the object case of abstract mass nouns.