How syntactic gradience in L1 affects L3 acquisition

The article reports on a longitudinal study of syntactic cross-linguistic influence (CLI) among L1 Polish learners of L2 English and L3 Norwegian. The study mainly aimed to determine the influence of gradience in L1 on third language acquisition. To this end, four syntactic properties were tested, two of which exhibit similarity between Polish and Norwegian (subject-oriented possessive pronouns and adverb placement), and the other two - between English and Norwegian (definite and indefinite articles). A group of 24 learners of Norwegian participated in an acceptability judgment task, which was administered at three data collection times in all three languages. It aimed not only to determine the presence (and sources) of CLI, but also to observe how gradience in L1 affects the assessment of equivalent properties in L3. In order to assess the role played by gradience, the trilinguals' performance was compared to that of a control group of English-Norwegian bilinguals. The data were analyzed with mixed-effects ordinal logistic regression modelling, which showed statistically significant differences in the ratings of articles between the two groups. We attribute this finding to gradient acceptability characterizing subject-oriented pronouns and adverb placement in Polish, which is a potential source of non-facilitative CLI.