Acquisition of Russian Voice Morphology: sja-Types in Monolingual and Bilingual Children

The Russian suffix -sja presents a learnability problem: a single morpheme signals five distinct argument-structure alternations (anticausative, reflexive, antipassive, reciprocal, and impersonal). How do monolingual and bilingual children acquire this complex form-function mapping? We report a longitudinal corpus study of 13 Russian-speaking children (five monolinguals and eight bilinguals) examining the emergence, distribution, and productivity of each sja-type. Three main findings emerge. First, children show a productivity hierarchy: anticausative and reflexive occur with many different verbs, whereas reciprocal and impersonal are largely confined to a few high-frequency items. Second, impersonal -sja is uniquely difficult, emerging latest and showing the lowest productivity overall. Third, contrary to predictions from heritage language research, bilingual children in our corpus show no deficit relative to monolinguals (and in fact show earlier emergence across the board). These findings suggest that the bilingual divergence from the monolingual baseline must emerge after early childhood.