Antipassive <Abstract> Antipassive constructions are derived intransitive constructions based on transitive verbs in which the patientive argument is demoted to an oblique position or left unexpressed. There are no dedicated antipassive markers in Slavic, but several subtypes of reflexive verbs meet the definition of antipassive. In particular, all Slavic languages have reflexive constructions in which the patientive participant remains unexpressed. The unexpressed participant is interpreted as unspecified in some reflexive constructions and as semantically incorporated in other constructions. Both subtypes of constructions are lexically restricted.</abstract> Definition An antipassive construction is generally defined as a derived intransitive construction that corresponds to the transitive construction headed by the same lexical predicate so that (i) the patientlike participant (P) from the transitive clause is encoded as an oblique or is left unexpressed and (ii) the agentlike participant (A) from the transitive clause is realized as the sole core argument (S) of the antipassive clause. The notion of antipassive was coined in the 1970s for ergative languages, i.e., for languages where the P and S arguments in underived constructions are morphosyntactically aligned together, whereas the A argument is encoded differently, e.g., by the dedicated ergative case. Examples in (1a–c) illustrate the basic intransitive, basic transitive, and antipassive constructions in Chukchi (Chukotko-Kamchatkan), correspondingly. (1a) ŋinqey pəkir-gʔi boy.ABS arrive-AOR.3SG ‘The boy arrived’ (1b) tumg-e ŋinqey rəyegtetew-nin friend-ERG boy.ABS save-AOR.3SG>3SG ‘The friend saved the boy’ (1с) tumgətum ŋinqey-ək ine-nyegtele-gʔi friend.ABS boy-LOC ANTIP-save-AOR.3SG ‘The friend saved the boy’ (Polinsky 2013) A growing body of research now argues that antipassive constructions must be acknowledged as conceptually possible and empirically attested in accusative languages, including Slavic (Heath 1976; Lazard 1989; Say 2008; Janic 2013). The encoding of the agent is not affected by antipassivization in accusative languages because here, the A and S arguments are aligned together. In ergative and accusative languages alike, antipassives are typically used for backgrounding the P participant and/or for emphasizing the agent’s involvement in the event. There are several construction types in Slavic that meet the definition of the antipassive above, cf. (2b) as opposed to its transitive counterpart in (2a).