Diathesis, or "valency alternation," refers to sentence structures that alter the roles of a verb, with the passive being a prototypical example. This book offers an extensive survey of diathesis in German, cataloguing nearly 250 distinct types, ranging from highly productive forms to those found in only a few verbs. The primary aim is to present this grammatical diversity in a cohesive manner while classifying and organizing the various diatheses. A summary of about 80 prominent diatheses is included, complete with newly created German terms for those that previously lacked names. The richness of diathesis in German may be surprising, yet it reflects a broader trend across languages, where diverse constructions around a lexical predicate allow for varied perspectives on events. Additionally, the book addresses epithesis, which maintains constant verb roles while expressing tense, aspect, mood, and evidentiality. The major epithesis constructions number around 40, significantly fewer than the diathesis forms, suggesting that diathesis represents a more complex grammatical topic than epithesis in German.
