“…It is an open question, therefore, as to whether the transfer effects in these two situations are comparable: is L1 influence in adult L2 learners (late bilinguals) similar to L2 influence in early bilinguals? In short, although there is some basic research that systematically compares L2 learners and heritage speakers -as well as research focusing on the systematic nature of incompletely acquired L1 grammatical systems in children and adults (Silva-Corvalán, 1994;Håkansson, 1995;Song et al, 1997;Anderson, 1999;Montrul, 2002;2004;Kondo-Brown, 2005;Polinsky, 2006;2008;Bolonyai, 2007) -this trend should continue. The findings from these research programs have much bearing on our understanding of the role of age on language acquisition and loss more generally, and they are crucial to inform linguistic theory and the heritage language teaching profession.…”