The paper analyses the structure of sentences like German Die Frist ist um (or English It's over), where prepositions without complements function as predicates. Several possible explanations for the occurrence of such forms are explored and found unsatisfactory, e. g. the assumption of elliptical constructions or of verb particles linked to the copula verb sein. Explanations limited to the German language cannot help, since the same kind of construction can be observed in other languages, too. However, this specific sentence type seems to be restricted to local prepositions, paralleling the syntactic distribution of local (but not modal, causal etc.) adverbs in this regard. Consequently, the general nature of local expressions in the languages of the world is being discussed, and the diachronic development of local prepositions in German is taken into account. It turns out that not only were all German local prepositions originally members of other word classes, but most of them still are adverbs. The astonishing fact that there is layering of different states of grammaticalization over such a long period of time explains why predicative use of local prepositions without complements is possible, while the specific treatment of these elements by itself points to the exceptional position - in cognitive terms - of local conception
