Contingency learning and perfective morpheme productivity in L2 Italian: A study on lexeme–morpheme associations with ΔP

Abstract This study utilized unidirectional association score ΔP to track perfective morpheme productivity in longitudinal spoken L2 Italian data. Research questions concerned whether early L2 perfectives were contingent upon telicity of predicates, whether lexeme–morpheme association changed as proficiency increased, and whether distribution of perfectives in the L1 input affected the patterns of morpheme emergence. Results showed that (i) the productive use of the perfective was contingent upon a few, infrequent telic predicates but also upon some actionally underspecified, very frequent general-purpose ones; (ii) a generalized decrease in association scores over time accompanied the productivity of the perfective morpheme; (iii) distribution of perfectives in L2 data did not reflect distribution in the L1 input. The statistical analysis adopted in this study is replicable to other domains where contingency of stem-affix alternations may provide cues for observing the developing L2 grammar