Cognitive-Diachronic Analysis of German Causal Conjunctions

The subject of the study is the functional differentiation of four key causal conjunctions in the German language: weil, da, denn, and sodass. These function words, traditionally categorized within the synonymous field of causality, form the core of the expression system of causal relationships in contemporary German discourse. The research focuses on the paradox of their limited interchangeability despite formal logical equivalence. The analysis addresses not only the synchronic semantic-pragmatic and syntactic properties of these conjunctions but also their deep cognitive representations. Furthermore, the subject area includes a diachronic component: the etymological origin of each lexeme and its historical trajectory of grammaticalization from specific spatio-temporal or textual schemas. Thus, the subject of the study encompasses the complex interrelationship between historical genesis, stable cognitive structure, and the current grammatical behavior of conjunctions, which allows for an explanation of the systemic nature of their distribution in the language. The study employs an integrative approach that combines three methods: diachronic analysis for studying the history of words, the theory of mental spaces for modeling their meaning, and construction grammar for describing their role in sentences. The scientific novelty of the research lies in the development of a holistic cognitive-diachronic model that explains the systematic specialization of conjunctions through the connection of their origin, mental representation, and grammatical form. It has been established that each conjunction activates a unique diachronically rooted scene. This allows us to demonstrate that their syntactic differences are not primary or arbitrary but are a grammatical consequence of deep cognitive schemas. Thus, the main conclusion of the work is the assertion that the choice of a causal conjunction is determined not by formal rules or style but by the necessity of activating the corresponding historically established mental scene. The results of the research contribute to the theory of grammaticalization and cognitive linguistics, and also have practical value for teaching the German language and tasks of automatic text processing.