My project is the first large-scale investigation of concessive conditionals (CCs) from the perspective of usage-based CxG. CCs are basically conditionals whose consequent holds under a range of antecedent values. Depending on quantificational strategy, CCs constitute a family of formally diverse constructions in many languages, ranging in German from the 'scalar' subtype (SCCs), which is based on conditionals, to the 'alternative' and 'universal' subtypes (UCCs, ACCs), which display strong family resemblances with embedded interrogatives and free relatives, respectively. Interrogative-like U/ACC protases are particularly intriguing as they are connected by intersective gradience to ‘irrelevance predicates’ with embedded interrogatives. Based on a quantitative and qualitative analysis of over 50,000 tokens from the DeReKo corpus, my project has three aims: to set up a constructionist micro-typology of German CCs, applying the concept of 'allostruction' to a new domain of grammar; to document the cline of grammaticalisation linking sentential irrelevance predicates to desententialised U/ACC protases; and to provide a formalised account (based on Inquisitive Semantics and Question-Under-Discussion theory) of the discourse basis motivating the link. The project thus contributes to the description of CCs in German on an empirical basis well beyond existing studies and can potentially serve as a model for other language-specific studies of CCs before a typological background.