Disentangling sources of incomplete acquisition: An explanation for competence divergence across heritage grammars

Abstract

This article brings to light an important variable involved in explaining a type of competence divergence in an instance of bilingual acquisition: heritage speaker (HS) bilingualism. We present results of experiments with European Portuguese (EP) heritage speakers (HSs), showing that they have full morpho-syntactic and semantic competence of inflected infinitives, similar to EP monolinguals. We show this constitutes clear evidence of competence mismatches between heritage speakers of European and Brazilian Portuguese, comparing our results to Rothman’s (2007) experimental evidence that Brazilian Portuguese (BP) heritage speakers lack knowledge of inflected infinitives. These comparative results are especially relevant because inflected infinitives were argued (Pires, 2002, 2006) to have been lost in colloquial BP dialects, although educated monolinguals demonstrate target competence. Neither incomplete acquisition nor attrition hinders the acquisition of inflected infinitives by European Portuguese HSs, raising questions regarding