Morphological Change Through Phonological Analogy: 2nd Person Singular -s → -st and Related Developments in Germanic

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.∗