This volume presents a collection of articles that share a focus on South Slavic languages and clausal complementation. They offer insights on this topic from various perspectives, taking up issues relevant not only for specialists of (South) Slavic languages, but also for the broader linguistic community interested in clause combining, areal linguistics, language contact, diachronic syntax and/or corpus linguistics. In their entirety, the studies assembled here cover the entire linguistic geography of South Slavic, including exclave varieties in Italy as well as contact with non-Slavic languages such as Albanian and Hungarian.The volume arose from the workshop "Variation in space and time: clausal complementation in South Slavic," which was funded by the Swiss National Science Foundation and organized by the editors on March 17-19, 2016, at the University of Zurich. Most of the contributors to this volume were also participants in that workshop. We thank every author for their continued motivation to contribute to this joint endeavor, which, as we hope, will help establish directions for the study of clause combining, in particular of clausal complementation, in Slavic languages in a modern framework. We are also obliged to an anonymous reviewer who provided thoroughgoing and valuable comments on every article and to Giulia Morra for her assistance in creating the index. Moreover, we thank the publishing house De Gruyter and, in particular, the editors in charge of the TiLSM series for taking our volume on board.