Human thought and action is fundamentally shaped by a small set of cognitive categories, such as time, space, causality, or possession. It is not surprising, therefore, that all natural languages have developed many devices to express these categories. Temporality, for example, is reflected in the lexical meaning of verbs, in grammatical marking of tense and aspect, in time adverbials, in special particles, and in the application of discourse principles. Many of these devices have been the subject of intensive research across languages; but as a rule, this research focuses on particular aspects, it does not look at the expression of such a category as a whole, which is precisely the aim of the present series. The short volumes bring together what is known about the expression of a particular category in human language.