The purpose of this thesis is to examine the occurrence of the definite article in possessive constructions. This is a comparative study, which focuses mostly on the usage and appearance of the definite article in the Hungarian language, paying particular attention to native Hungarians, who live in Transylvania in a bilingual environment among Romanian speakers. The grammar of these two languages are totally different, and thus the question arises whether they have a systematic impact on each other or not. The main hypothesis is that Hungarian speakers who live in Romania are less likely to accept the definite article omission, because Romanian possessive noun phrases are inevitably and without exception definite.