The project is concerned with the role of negation as part of complex adjectives in German. We propose a case study on a certain type of adjective such as unaufhörlich ‘incessant’, unglaublich ‘unbelievable’, or unvergesslich ‘unforgettable’. These adjectives are highly interesting since they appear to be transparent in interpretation, but their positive base (a) does not exist, (b) is said to be rare, or (c) means something else. We refer to them as BNDAs: Baseless Negative Derived Adjectives. The goals of this project are to provide a complete collection of BNDAs and their licensing conditions, to trace their development from Old High German to Present Day German using corpus-linguistic methods, and to propose a formal semantic analysis. Our main hypothesis is that the non-existence or rareness of the positive bases and the difference in meaning is systematic, contrary to what is assumed in the literature: The positive bases of BNDAs require a negation (or a degree modifier, e.g. kaum glaublich ‘hardly believable’) in order to be licensed and some of the peculiarities observed with the positive bases are similar to those of NPIs (a,b), or there is some other operation that makes word-internal negation possible: passivization, for example, in the case of (c). Through our research, we will gain a better understanding of how negation interacts with other meaning components by revealing the mechanism of diachronic change below the word-level. This work forms an ideal basis for cross-linguistic explorations. Russian for example seems to have less restrictions for un-formation with negative adjectival roots and English allows un-formation with verbal roots. In addition, it seems to be the case that other languages also have BNDAs pointing to the fact that they are universal.