Advances in Formal Slavic Linguistics 2017 is a collection of fifteen articles that were prepared on the basis of talks given at the conference Formal Description of Slavic Languages 12.5, which was held on December 7–9, 2017, at the University of Nova Gorica. The volume covers a wide array of topics, such as control verbs, instrumental arguments, and perduratives in Russian, comparatives, negation, n-words, negative polarity items, and complementizer ellipsis in Czech, impersonal se-constructions and complementizer doubling in Slovenian, prosody and the morphology of multi-purpose suffixes in Serbo-Croatian, and indefinite numerals and the binding properties of dative arguments in Polish. Importantly, by exploring these phenomena in individual Slavic languages, the collection of articles in this volume makes a significant contribution to both Slavic linguistics and to linguistics in general.