This study explores the grammar of focus particles in German. It gives a thorough description and analysis of focus particle constructions and links their syntactic, semantic, and information structural properties to their prosodic characteristics. The study also shows that focus particles present a particularly well-suited subject for the investigation of the modularity of grammar in general. The first part of the book deals with the syntax, semantics, and pragmatics of focus particle constructions and results in a modular account of the relation between their word order, information structure, and meaning. The second part presents a corpus study and several speech production and perception experiments investigating the prosodic realization of the constructions. The integration of these two lines of research results in a comprehensive theory of focus particles and of the interaction of grammar and information structure in German.