Representational and Computational Changes in Heritage Language Grammars

The notion of complexity has been applied to descriptions and comparisons of languages and to explanations related to ease and difficulty of various linguistic phenomena in first and second language acquisition. It has been noted that compared to baseline grammars, heritage language grammars are less complex, displaying morphological simplification and structural shrinking, especially among heritage speakers with lower proficiency in the language. On some recent proposals of gender agreement in Spanish and Norwegian (Fuchs et al., 2015; Lohndal & Putnam, 2020), these differences are representational, affecting the projection of functional categories and feature specifications in the syntax. An alternative possibility is that differences between baseline and heritage grammars arise from computational considerations related to bilingualism, affecting speed of lexical access and feature reassembly online in the minority language. We illustrate this proposal with empirical data from gender agreement and differential object marking. Although presented as alternatives, the representational and computational explanations are not incompatible, and may both be adequate to capture varying levels of variability modulated by linguistic proficiency. These proposals formalize bilingual acquisition models of grammar competition and directly relate the availability and type of input (the acquisition evidence) to the locus and nature of the grammatical differences between heritage and baseline grammars.