Abstract This article investigates the development of declension classes in parts of West Central German with historical and regional data. The focus lies on the plural marking of nouns belonging to the neuter a -declension and the feminine ō -declension. The analysis explores the formation of distinct plural markers from the 11 th to the 19 th century. The diachronic and diatopic distribution patterns are elucidated and related to semantic factors such as animacy. The study confirms that number strengthening ( Numerusprofilierung ) is a central motive for diachronic change in noun inflection and highlights the influence of phonological processes on the organization of declension classes.
Fromm et al. (2026) studied this question.