Abstract In order to contribute to the understanding of the nature of inflection, this paper investigates the endings on pre-nominal adjectives in four Germanic languages: Dutch, Norwegian, German, and Yiddish. Incorporating detailed observations about Yiddish in general and non-canonical nominals in particular, this study confirms Harbert’s (The Germanic languages, Cambridge University Press, Cambridge 2007) classification of the Mainland Scandinavian languages as semantically determining their inflections but of German as encoding case, number, and gender on its endings. The latter is shown to be regulated by lexical factors. Dutch is grouped with Norwegian and Yiddish with German. While all four languages differ in their details, the paper proposes that compared to Dutch, the Norwegian weak inflections require a subset of definiteness (sub-)components and that in comparison to German, the Yiddish weak inflections require a subset of lexical triggers. Whereas weak endings only surface inside DPs, which are necessarily definite in Dutch and Norwegian, strong endings are shown to appear in more diverse contexts. Given the language-specific conditions on the distribution of the weak inflections, the strong endings are interpreted as the elsewhere case in all languages.