The aim of this habilitation treatise is to contribute to the methodological discussion about the treatment of exceptional, non-canonical, and mismatch phenomena in linguistic research and the implications such phenomena have for linguistic theory. Based on a survey of the current state of the art in work on the theoretical status of exceptional phenomena, five case studies of non-canonical word order phenomena, such as predicate clefts and right-dislocations, and morphology-semantics mismatch in the verbal domain, are reassessed in terms of two main questions: (i) in what way(s) are the phenomena dealt with exceptional and (ii) how does the way they have been dealt with advance our understanding of the nature of exceptional phenomena and their implications for linguistic theory. One of the main contributions of the treatise is that it offers a functional perspective towards exceptional phenomena in syntax and morphology by establishing a connection between their exceptional status and the semantic and pragmatic effects they give rise to. It moreover extends existing typologies of approaches to exceptional phenomena that are mainly based on syntactic research by pinpointing ways of dealing with such phenomena in semantic and pragmatic research.