This paper investigates variation in the usage of be and have with participles of mutative intransitive verbs by the Late Modern English grammarian Joseph Priestley. His usage, as exemplified by a corpus compiled from his private manuscript letters, is compared with a reference corpus and with the “rules” in his own grammar. The study shows that Priestley’s usage reflects the general change for this linguistic feature from a predominant use of be to a greater occurrence of have in the late eighteenth century, as discussed by Rydén & Brorström (1987). It is also shown that when compared to his grammar, Priestley’s usage upholds his reputation as an early descriptivist.
