Are heritage speakers one step ahead in ongoing processes of diachronic change?

Abstract This study investigates whether heritage speakers of European Portuguese (EP) show a diachronically advanced behaviour in their comprehension of null object constructions. Based on a comprehension experiment, we compared heritage speakers to homeland speakers of EP, on the one hand and homeland speakers of Brazilian Portuguese (BP) on the other, the latter representing a variety in which null objects have diachronically spread. Our results confirm significant differences between EP homeland speakers and the two other groups but not between heritage speakers and BP homeland speakers, indicating an acceleration of diachronic change in the heritage speaker group. In addition, our study confirms that null objects in islands are available to homeland speakers of EP, challenging earlier analyses of null objects in this variety.