There has been a substantial amount of research on heritage language acquisition and diachronic change. Although recent work has increasingly pointed to parallels between those two areas, it remains unclear how systematic these are. In this paper, we provide a bird's eye view, illustrating how patterns of diachronic change are mirrored in heritage language grammars. In doing so, we focus on one of the best-described grammaticalization processes – namely, the formation of articles from demonstratives and numerals, reviewing studies on heritage varieties which mirror those processes. Based on this review, we make two main points: that change in heritage language can be predicted based on established diachronic scenarios, and that heritage languages often amplify incipient changes in the baseline. After discussing a number of attested changes in a bilingual context, we identify directions for future research in the domain of determiners in heritage languages.