The focus of this paper is about the copula+infinitive in Modern German, its older stages, and its dialectal and sociolectal varieties. In doing so, the paper comes to conclusions different from other discussion of this topic, mainly Demske 1994. The prepositional infinitive and the verbal substantive (gerund) in modern German are not only minimally distinct syntactic structures, but they also have a clear sociolectal distribution: gerunds are more or less restricted to the spoken dialects with the prepositional infinitive/PI being banned from South German/SG, while the PI is the standard in Modern German/MStG. It is shown that the historically original gerundial form was heavily underspecified with respect to a number of grammatical codes. The prepositional infinitive, which grew out of this gerund due to the later demise of case coding on the infinitive, lost the original multiplicity of meaning to make room for only one meaning component: the modality of necessity. Attention will be drawn to adjacent meanings that the modern dialectal gerund encapsulates: the tough-movement construal, the modal
passive, and both reason and purpose embedded question infinitivals. Languages other than German adduced for comparison are Gothic, Old and Middle English, modern Dutch, and Polish. Next to tough-construals and their structural and semantic conditions, also sluicing construals are considered and discussed in some detail. Yet, the main question this discussion pursues is why it is that the oral-only coded sociolects (and their historical predecessors) take recourse to the old gerundial forms, while the modern written standard of German developed the prepositional infinitive – either formal variant almost entirely to the exclusion of the other.