The Role of Defaults in the Acquisition of Basque Ergative and Dative Morphology

Abstract The use of default agreement plays a key role in morphological theories from diverse perspectives, as well as in many analyses of child language acquisition. In this paper, the development of ergative and dative agreement and case in 20 bilingual and 11 monolingual Basque-speaking children between 2;00-3;06 years old is examined. I propose that the most commonly-produced errors in child Basque involve the substitution of unmarked absolutive forms for ergative and dative case and dative verbal morphemes; for independent reasons, the absolutive is considered to be unmarked inflection in adult Basque (Arregi and Nevins, 2012). These errors suggest that in early stages of morphological acquisition, children learning Basque use default forms which encode a subset of the morphemes as a “best match” to support their developing language when they are unable to produce or retrieve target forms.