Subject clitics in English

As a counterexample to unidirectionality in grammaticalization, Newmeyer (1998:270) cites the loss of second-person singular subject clitics, e.g., in hastou and wiltou, in 16th century English (Kroch et al. 1982). These forms are a common, albeit optional, feature of Middle English. Though full thou forms replace -tou/-tow clitics in Early Modern English, second-person plural enclitics, subject proclitics, and object enclitics attest to the continued viability of clisis. This paper argues that -tou/-tow is a reduced form, not a clitic, its disappearance being attributable to loss of a phonological rule, not decliticization. This change predates the replacement of thou by you, the non-expression of subjects in imperatives, and the spread of do in questions and is sudden rather than gradual.