Acquiring differential object marking in heritage Spanish: Late childhood to adulthood

Aims/objectives/purpose/research questions: The present study evaluated child and adult heritage speakers’ (HSs) productive and receptive knowledge of differential object marking (DOM) and addressed the roles of age, proficiency, and frequency of use in explaining variability. Design/methodology/approach: A total of 127 participants completed a sentence completion task (SCT) and a morphology selection task (MST) targeting DOM with animate and specific direct objects. Fifth grade, seventh/eighth grade, and adult HS groups participated alongside a group of Spanish-dominant bilingual adults. Data and analysis: All responses were coded for DOM and submitted to binomial logistic regressions, which included effects for group, task, proficiency, and frequency of use of Spanish. Findings and conclusions: HSs’ DOM production and selection increased across age groups. Proficiency modulated differences between HSs of all ages and participants were more likely to select DOM than to produce it, particularly if they used Spanish less frequently. All HSs produced and selected DOM at least one time, but many differed from Spanish-dominant bilingual adults. Originality: This study is the first to plot the course of development across late childhood and into adulthood in Spanish HSs that incorporates both a production task and a receptive measure to explore HSs’ holistic linguistic systems. Significance/implications: These findings show that there are factors that can account for variability in the production and selection of DOM at the group, individual, and within-speaker levels. This has implications for theories of acquisition: gradient knowledge is inconsistent with incomplete acquisition of DOM, but the increase in knowledge across age groups does not support feature reassembly.