INTRODUCTION

Conditional (if–then) constructions directly reflect the characteristically human ability to reason about alternative situations, to make inferences based on incomplete information, to imagine possible correlations between situations, and to understand how the world would change if certain correlations were different. Understanding the conceptual and behavioural organization of this ability to construct and interpret conditionals provides basic insights into the cognitive processes, linguistic competence, and inferential strategies of human beings.

The question of what a conditional construction is may be answered in many different ways, and from many different perspectives. The linguistic characterization of conditionals in different languages provides the basis for linguistic universals, which presumably at least in part constrain the way we reason. The diachronic point of view provides knowledge of the possible adaptations that a system of conditionals may undergo, and may detect dependencies on developments in other linguistic domains. Studies of language acquisition provide additional perspectives on a linguistic system, offering not only developmental data but also insights into the basic components and relationships of the adult system.