Published online by Cambridge University Press: 15 February 2019
Almost all existing accounts of the change of the 2nd person singular verbal agreement ending -s to -st in Old English and Old High German attribute the development to some combination of reanalysis of forms with enclitic subject pronouns ending in -stu and analogy based on a handful of mainly preterite-present verbs that already had 2nd person singular -st in the present indicative in Proto-(West)-Germanic. These factors retain a role in the analysis presented here, but I argue that the operative mechanisms are essentially phonological in nature, licensed ultimately by certain neutralizing processes such as degemination, rather than involving the spread of an existing -st morpheme, grammaticalization of an enclitic subject pronoun, or relocation of a morphological boundary. This analysis also sheds light on the relationship of the 2nd person singular change to the more general phenomenon of word-final t accretion seen in dozens of words such as German Axt ‘ax’ < Middle High German ackes or English against < earlier agains.*
Special thanks to Jean-Pierre Koenig and to two anonymous referees for JGL for valuable feedback on earlier versions of this paper and to the attendees at my presentation at GLAC 23 (April 2017), which dealt with some aspects of this project.