Classification and Functional Significance of Key Lexemes

The primary aim of this study is to examine the role of core lexemes as system-forming elements in lexical organization and to develop principled criteria for their identification and classification. The research seeks to determine how core lexemes function within semantic fields and how they generate derivational, combinatorial, and discourse-level units.
To achieve these objectives, the main tasks of the study include defining diagnostic parameters of lexical dominance, formulating a structured classification model, and demonstrating its applicability through systemic and cognitivelinguistic analysis.
Furthermore, the methodology integrates structural-semantic analysis, semantic field modeling, prototype theory, and corpus-informed observation. The proposed Core Lexeme– Unit Matrix (CLUM) serves as the analytical framework, combining semantic centrality, morphological productivity, collocational stability, and discourse recurrence as identifying criteria. Comparative insights from semantic-field research on idiomatic expressions further support the gradient nature of lexical units.
The results indicate that core lexemes are not merely high-frequency words but function as organizing nodes within lexical systems. Their structure reflects a hierarchical core–periphery continuum, extending from basic embodied meanings to abstract conceptual domains (inflectional paradigms, derivational families, phraseological units, and discourse formulae). The findings demonstrate that lexical centrality is multidimensional and cognitively motivated. The paper’s contribution is an analytical model that makes the author’s position explicit: core lexemes are best identified by the convergence of semantic centrality and patterned usage.
Finally, the discussion highlights the theoretical implications for systemic lexicology, cognitive linguistics, and corpus-based research. The study concludes that core lexemes constitute dynamic conceptual anchors within the mental lexicon and communicative practice, offering a replicable framework for lexical analysis across languages. An important theoretical contribution of this paper is therefore a strengthened interface claim: core lexemes are a privileged observation point for lexicon–grammar–discourse interaction.