Present-day sonata theory scholarship increasingly draws on a typology of sonata forms that consists of five interrelated types, placing particular emphasis on the double return and thematic rotation. The present article aims at scrutinising a variety of formal phenomena in the Classical repertoire that potentially challenge, in one way or another, the established sonata-form typology and its analytic application. This includes the early double return, strong off-tonic cadences within the recapitulatory action space, false recapitulations as well as false-false recapitulations, recapitulations launched with P-based S and off-tonic recapitulations. The article concludes with a reflection on the epistemological status of the sonata typology and discusses the notion of a modularly conceived Formenlehre.