The aim of this work is to provide the reader with access to the great variety of data that has emerged in the area of grammaticalization over the past 30 years. It presents data from diverse language families, providing examples of 400 processes from 500 languages. In their introduction, the authors lay out a classical definition of grammaticalization and discuss inherent problems and conventions chosen to best present the data. The second section provides a list of grammatical terms adopted with definitions and clarifies differences of usage.

The third section is the lexicon, alphabetized by source concept. Most entries are exemplified with textual data and glosses. The authors make general observations when a process can be readily related to semantically similar entries. They also provide biographical references to relevant work. Appendixes 1 and 2 allow the reader to look up an entry either as a source or target. Finally, appendix 3 gives a list of languages mentioned and their genetic affiliation.

This volume is well conceived in its timeliness and sensitivity to the needs of its readers. For scholars of grammaticalization, it provides easy access to data and biographical information. Appendixes allow great flexibility in how the lexicon is used by confirming suspected relationships, enriching analyses with further data, or expanding hypotheses to include unexplored relationships. For linguists in any other field, it should provide insights into diachronic and cognitive processes that lead to synchronic universals. Contradictory proposals for directionality, such as an H-POSSESSIVE > EXIST, and EXIST > H-POSSESSIVE, may be disconcerting. As the authors suggest, this conflict may involve a more extensive pathway with two types of semantic existence. Alternately, the conflict may be resolved by a common source for EXIST and H-POSSESSIVE from a LOC COPULA, EXIST having an optional locative complement and H-POSSESSIVE a human location. This work is essentially a summary of what is known in the field and should lead to broader explanatory principles.