This excellent cross-linguistic study, a lightly revised version of the author's 1993 Free University of Berlin dissertation, represents a major contribution to our knowledge and understanding of indefinite pronouns, both synchronically and diachronically. Haspelmath has investigated in some detail data from forty languages and to a much more limited extent data from 100 other languages of global geographical distribution. In the forty-language sample, Haspelmath was constrained by the availability of information, and this necessarily created a bias toward Indo-European (22/40) and especially European languages (30/40, if the Caucasus is considered part of Europe). Haspelmath defends the representative quality of this group by noting that indefinite pronouns are diachronically unstable, so that even closely related languages differ substantially in their systems of indefinite pronouns.Following brief chapters synopsizing the structure of the book and delimiting the scope of the inquiry, Haspelmath examines the main formal and functional types of indefinite pronouns (chap. 3, pp. 21-57) and finds these to consist primarily of interrogative pronouns, less frequently generic ontological category nouns like person, thing, place, time, manner, and so on, and occasionally the numeral one. These typically occur in series (e.g., English some-, any-, no-), in which the formal element shared by all members (in English, each of the morphemes just noted) is the indefinite marker. One of the interesting results to emerge from this survey is that indefinite pronouns are as a rule derived forms which do not themselves serve as derivational bases for other pronoun types. Consequently, an artificial language like Esperanto, which employs for its indefinite pronouns a bare base from which both interrogative and negative pronouns are derived (iu, 'somebody' : kiu 'who?' : neniu 'nobody'), represents in this regard a nonoccurrent type of human language. Haspelmath discerns nine different functions for indefinite pronouns, and these are presented in chapter 4 (58-86) in an implicational map having the following form: