Spoken language is characterized by the occurrence of linguistic devices such as discourse markers (e.g. so, well, you know, I mean) and other so-called “disfluent” phenomena, which reflect the temporal nature of the cognitive mechanisms underlying speech production and comprehension. The purpose of this book is to distinguish between strategic vs. symptomatic uses of these markers on the basis of their combination, function and distribution across several registers in English and French. Through deep quantitative and qualitative analyses of manually annotated features in the new DisFrEn corpus, this usage-based study provides (i) an exhaustive portrait of discourse markers in English and French and (ii) a scale of (dis)fluency against which different configurations of discourse markers can be diagnosed as rather fluent or disfluent. By bringing together discourse markers and (dis)fluency under one coherent framework, this book contributes to corpus-based pragmatics, discourse analysis and crosslinguistic fluency research.