Abstract
The article aims to introduce the formal development of the verb _ tun _ in the German language, based on the corpuses of old, middle and modern-new-high-German language. However, the morphological analysis is primarily based on Józef Darski’s innovative model of linguistic analysis which, due to its synchronic cha racter, has been adopted in diachronic research. The verb forms of _ tun _, prone to modifications owing to multiple processes depending on both the stage of development and the language as a paradigm, reveal its capability of adaptation to the two basic classes of verbs, i. e. strong verbs and/or weak verbs and their subclasses. Additionally, it is possible to observe the processes of homogenization of the verb forms within a given paradigm and among the forms of distinct paradigms, mainly to stabilise them.