Stability and change in heritage grammar: Variable object expression across generations of Canberra Vietnamese

Abstract Research on heritage languages predicts that contact-induced change is selective: Some variables shift while closely related ones remain intact. Fine-grained variationist evidence for this prediction, however, remains limited. We test it by analyzing object expression in Canberra Vietnamese, a community in which generational restructuring of subject expression is already documented. Contrary to the pattern found for subject expression, object expression remains systematically conditioned by Coreferentiality and social network language across generations, with only one localized generational effect: In second-person reference, Gen2 speakers shift from kin terms to pronouns. Read together, this pattern indicates that change targets particular variables rather than sweeping through the grammar. Examining multiple related variables within a single community is therefore necessary to capture the structured, uneven nature of change in heritage languages.