The book describes a large fragment of a grammar of German in terms of the HPSG paradigm. On a broad empirical basis it develops a formally explicit theory with special emphasis on various word-order phenomena: the relatively free position of constituents in the midfield with reference to coherent constructions, positioning in the verb complex, initial-field occupancy, and extraposition. The analysis of these phenomena is embedded in a general theory of sentence structure and a discussion of relevant formal mechanisms.