Ultimate attainment in heritage language speakers: Syntactic and morphological knowledge of Italian accusative clitics

Abstract

AbstractThe acquisition of a heritage language, normally the weaker language of early bilinguals, has been oftentimes defined as incomplete, especially for morphosyntax. As a result, these early bilinguals resemble late bilinguals more than native language speakers, calling into question the role of age of exposure. The effects of syntactic complexity on knowledge of morphosyntactic structures, however, have not been sufficiently considered hitherto. This study investigates age of exposure and syntactic complexity by comparing heritage, second language, and native language speakers on knowledge of Italian accusative clitics in three structures. An oral structural priming task and a speeded grammaticality judgment task find a discrepancy in the level of ultimate attainment heritage speakers reach for syntax and morphology. While their abstract representation of clitic structures approximates that of native language speakers more closely, their morphological knowledge of clitics aligns with second language speakers, suggesting early exposure has tangible effects only on syntactic knowledge. In turn, syntactic complexity affects the representation of clitic structures in a predictable manner, but is inconsequential to explicit knowledge of morphological forms in monolingual and bilingual speakers. Lack of age of exposure effects in the morphological domain are attributed to interface vulnerability.