The research in this paper is focused on the apprehensive function of the particles da ne in Macedonian and da ne bi in Bulgarian as part of South Slavic subjunctive da-constructions. These clusters of particles are considered to be markers of a wider apprehensive-epistemic category. They are assumed to have undergone grammaticalization due to their morphosyntactic and prosodic unity. Even though there may be some contextual differences, these particles in both Balkan Slavic languages share a common semantic component: an undesirable "fear-causing" possibility of some potential situation. In terms of distribution, they may occur in both dependent and main clauses expressing related, gradient apprehensive-epistemic meanings. The goal of the paper is to categorize the apprehensive-epistemic types, determine their specific structural and functional properties, and establish the conceptual links between them. The paper takes a functional approach to the analysis of the apprehensive-epistemic semantic category, thus the categorization of its subtypes is determined on the basis of their functions in context. The analysis of the collected examples instantiating these functions testifies to an existing gradience within this category in both dependent and independent use. The conclusions of the paper have typological relevance in view of the fact that they may contribute to a better understanding of this crosslinguistic category from both semantic and grammatical perspective.