Conditional constructions have long fascinated linguists, grammarians and philosophers. In this pioneering new study, Barbara Dancygier and Eve Sweetser offer a new descriptive framework for the study of conditionality, broadening the range of richly described conditional constructions. They explore theoretical issues such as the compositionality of constructional meaning, describing both the mental-space building processes underlying conditional thinking, and the form-meaning relationship involved in expressing conditionality. Using a broad range of attested English conditional constructions, the book examines interconstructional relationships. Within the framework of Mental Spaces theory, shared parameters of meaning are shown to be relevant to conditional constructions generally, as well as to related temporal and causal constructions. This significant contribution to the field will be welcomed by a wide range of researchers in theoretical and cognitive linguistics.