Verbal Inflection, Feature Inheritance, and the Loss of Null Subjects in Middle English

This paper investigates how null subjects, generally termed pro in the literature, were licensed and lost historically in English, with special emphasis on the role of verbal inflectional morphology. It is revealed through a corpus search that pro was licensed as a null topic in Old English and Early Middle English but subsequently lost in Late Middle English. This coincides with the period in which English underwent a drastic typological change, going from a topic-prominent language to a subject-prominent language. In order to relate these simultaneous changes, I maintain that the loss of pro and the typological change to the language both resulted from the shift of f-features from Top(ic) to Fin(ite) within the hierarchy of fine-grained functional heads in the CP domain à la Rizzi (1997), and that this is ultimately attributable to the decline of verbal inflectional morphology for number agreement. Thus, as far as the analysis advanced in this paper is successful, the changes under discussion present an intriguing case of syntax–morphology interface in the domain of language change, where micro-level morphological attrition finally results in a large-scale typological shift of a language.