Deborah Arbes (ed.), Number categories: Dynamics, contact, typology (Studia Typologica 32). Berlin: Mouton de Gruyter, 2023. Pp. vii + 183.

The miscellaneous book under review is a collection of papers dealing with the category of number in different languages and under different perspectives.After a very short preface by the editor, the book is composed of five different chapters, all of which are based on presentations given at a pre-conference workshop on 'number categories' for the 4th Diversity Linguistics Conference on 3 June 2021, in Bremen, Germany.The chapters do not follow any particular thematic order but analyze some phenomena related to (nominal) number.Chapter 1, 'The tonal marking number on nominals in the Wagi dialect of Beria', by Katharina Gayler, Elsadig Omda Ibrahim and Isabel Compes, investigates number marking through tonal changes on nominals and noun phrases in the only surviving Eastern Saharan language Beria, spoken between Chad and Sudan.More specifically, the chapter focuses on Wagi (undocumented so far), one of the four different varieties of Beria.After presenting some phonological and morphosyntactic properties, the authors point out that Wagi shows three tones that can be combined, resulting in at least six different combinations (but probably more), and these allow phonemic distinctions both at the lexical and the morphological (number on nouns and verbs) levels.So, Wagi displays seven different nominal classes (where 'nominals' include nouns, property concepts, possessive pronouns and specifiersbasically demonstratives and anaphoric markers) according to which tonal contour they present in the singular forms and in the plural forms.However, on the one hand, even though they are all treated as nominals, only nouns display all the classes while adjectives inflect for only four of them and possessive pronouns only for two.On the other hand, specifiers are nominals as well but cannot be subsumed under the seven classes from an inflectional point of view since they have a middle tone for the singular and a low-high tone for the plural, a pattern not attested for nouns.In the NP, the number (tonal) distinction is marked just once on the last element of the phrase (the modifier, as Beria is a head-initial language or the head itself if no modifier is present), and thus, the NP takes the inflectional strategy of the nominal class of the modifier ('modifier pattern') and not the head nominal pattern.This chapter provides an in-depth preliminary description of the number system in a highly under-documented variety of Beria, which is of particular interest both from a micro-typological and descriptive perspective for Saharan languages but also for the general typology of number given the several peculiar 1