On language acquisition and language change. Is transmission failure favoured in multilingual heritage contexts?

Whether multilingual heritage settings can lead to imperfect language acquisition and language change is debated in the literature (Lightfoot 1991, Meisel 2010, Montrul 2004, Montrul/Potowsky 2007, Pascual Y Cabo/Rothman 2012, Silva-Corvalán 1994, Sorace 2004). By investigating the syntax of subject pronouns and the pro-drop parameter in pre-school children (aged 4.7-6.5) in one such context, this paper provides evidence that they do not. It is shown that all considered children acquired the pro-drop parameter target-like in both languages. The reduced system of subject pronouns instantiated in the heritage language by two children is shown not to follow from imperfect acquisition, but from their being simultaneous bilinguals, who have been exposed to less input in the heritage language than successive bilinguals. On this basis, we conclude that language acquisition in heritage contexts follows the general mechanisms of successive and simultaneous bilingual language acquisition, and does not automatically lead to transmission failure (Meisel 2007, 2010).