SUMMARY
Differences in the formalization of the semantic category of definiteness / indefinitenessBasing on theoretical contrastive studies guidelines, the article defines the semantic category of definiteness/indefiniteness where two basic opposition meanings are being ascribed to. It also distinguishes crucial sub-meanings for this category. The category established like this constitutes a characteristic interlanguage typical of theoretical contrastive studies, which is here used as tertium comparationis for demonstrating the formal differences between Polish, Lithuanian and dialectal exponents to express particular sub/meanings. The differences demonstrated in the article are to confirm a different degree of the formalization of the category in each of the natural codes compared here. The idea of taking the local dialect of Punsk into consideration results from a clearly visible influence of Polish and Lithuanian on the traditional dialectal system. In consequence, the dialectal system of exponents to express the meanings within the semantic category of definiteness/indefiniteness keeps a high degree of the traditional exponents specialization on one hand, but on the other hand, a low degree of specialization is being ascribed to some forms borrowed from Lithuanian (as a consequence of the Polish language influence), which results from the bilingualism of the Lithuanians living in Poland.