This book has grown out of many years of both authors' fascination with conditionals and conditional meaning. Each of us independently embarked on her own if-project in the early 1980s; we met for the first time at the 1984 meeting of the LSA (Linguistic Society of America), and from that moment we were bouncing ideas off each other and finding more and more in common. Eve's work reached a larger audience in 1990, with the book version of her Ph.D. thesis, while Barbara's book came out in 1998, following a long series of articles. Both books contribute in crucial ways to what we now understand conditionals to be about. Eve's idea of cognitive domains and Barbara's concept of predictive versus non-predictive conditionality are still basic to the framework we present to the reader now.

By the time our individual projects were completed we were both very much aware of the questions which, in our shared understanding of a descriptively and theoretically satisfying framework, remained unanswered. We knew that more attention needed to be paid to the analysis of conditional meaning and usage which could transcend the boundaries of formally explicit categories such as if-sentences. At the same time we were convinced by our experience of the data that the goal could be achieved only by focusing consistently on the systematic correlations between form and meaning, rather than just on morphosyntax or on semantics and pragmatics.