The article describes the consonant system in the speech of Potarje, an area in Northern Montenegro. The speech belongs to the East-Herzegovinian dialect, which at the margins displays transitional and mixed character. The specificity of this geolinguistic area is in that it testifies to the language being a living category and demonstrates that an administrative boundary in linguistics and the language itself is not necessarily a boundary between "languages," but rather a border area between different speeches. This applies to the area between Montenegro, Bosnia and Herzegovina, and Serbia. The mixed speech is characteristic of the Muslim "language oasis" far from the border, in the village of Lever Tara. Methods of research were based on fieldwork, records, audio recordings, as well as descriptions and comparisons within the speech and with the neighbouring speeches, and those relevant for the explanation of certain speech phenomena. Our goal was to present the material, its descriptions and comparisons without any pretensions to provide a full explanation of the speech lines.