The field of verbal aspect has been a focus for the derivation of a multiplicity of theoretical approaches ranging over decades of linguistic research. From the point of view of recent studies, though, there has been relatively little emphasis on the nature of the interaction of aspect with other categories, and the ways in which our knowledge of aspect acts as a primary semantic contributor to the creation of other basic verbal parameters such as tense and modality. This book aims to cross some of the categorial borders, using a collection of studies on the interfaces of English aspect with other grammatical domains. The studies in the book have been assembled in order to answer two central issues surrounding the nature of English aspect: the possibility of the historical co-existence of a perfective and imperfective grammatical distinction in English, and the derivation of modality as an inference arising out of specific conflicts and combinations of lexical and grammatical aspect. In answering these questions, a data-driven, rather than a theory-driven approach is favoured, and the general principles of Gricean pragmatics and grammaticalisation are applied to a wide range of empirical sources to propose alternative explanations to some long-established problems of English historical linguistics and semantics.