Edited by Claudia Claridge and Birte Bös
[Current Issues in Linguistic Theory 346] 2019
► pp. 77–110
For a long time, the striking similarities between OFris (Old Frisian) and Old English (OE) were attributed to an exclusive shared ancestor (Anglo-Frisian), but in the late 20th century that view was ousted in favor of a dialect continuum model. Recent developments in genetics, textual analysis, and archaeology, however, suggest that the earlier model is more accurate. This paper explores a series of diagnostics to distinguish between shared grammaticalizations caused by linguistic relatedness and those caused by geographical proximity. Those diagnostics are then applied to two developments exclusive to OFris and OE: the grammaticalization of aga(n) ‘have’ into auxiliary ‘have to’, and the development of a verb complement based on the OE/OFris present participle. In both cases, the diagnostics indicate that the changes occurred due to a shared ancestor, supporting the Anglo-Frisian hypothesis.