As the localized varieties of English used around the world, World Englishes (WE) have attracted great scholarly interest over the past 40 years. Differing with the previous linguistically-oriented WE studies, Axel Bohmann takes a multifeature, cross-varietal perspective to linguistic variation across the globe in his book, Variation in English World-Wide: Registers and Global Varieties. With a large corpus of texts, the author presents a general overview of variation by demonstrating potential linguistic similarities and differences between international varieties of English, and challenges the importance of geography in mediating linguistic differences in WE research. This book is a timely addition to the study of linguistic variation in the buoyant field of WE. Researchers interested in WE will find it a useful source for gaining a deep understanding of empirical-linguistic accounts of differentiation in English variation.

The book consists of nine chapters. Chapter 1 begins with an outline of the major theoretical and methodological issues on WE, aggregation-based linguistics and multidimensional (MD) analysis. The author points out WE are approached broadly from linguistic and national-historical perspectives after tracing the development of WE research. In terms of approach, the aggregation-based methods find productive application in the study of English variation, which incorporates patterns of co-variation among plenty of individual linguistic features. These practices take register variation as an agnostic position rather than an equal factor. In comparison to the former, the MD analysis places emphasis on the situational-functional context, and views linguistic differences as functions of different situations. Bringing such approaches together, a comprehensive analytical framework is employed to describe variation in geography and register.

Chapter 2 presents an introduction to the extralinguistic determinants of structural variation across a range of communicative situations, focusing on geographic variation and register variation in WE. The author discusses the dominant theoretical models in investigating geographic relations, and further states that there is a disconnect between the level of theorizing and a lack of comprehensive accounts of differentiation. In addition to geography, this chapter addresses a confounding factor of register variation within the framework of MD analysis, which offers a complementary perspective to English register studies. This is followed by how geography and register interact in structuring linguistic variation. As the author puts it, a more accountable analytic perspective ‘would be to quantify the influences of variety and register alongside each other’ (p. 40).

Chapter 3 compares different perspectives on the analysis and quantification of linguistic variation. The author provides explicit descriptions and comparisons of the Labovian study of language variation and change (LVC) as well as the text-linguistic perspective. Concerning the LVC, the paradigm is more suited for a detailed analysis of individual constraints and less attuned to overall characteristics. Compared with the Labovian paradigm, the text-linguistic perspective assumes more natural and intuitive to variation, which is suitable to give a holistic account of linguistic variation. After discussing two paradigms in isolation, the feature-aggregation approaches associated with dialectometry and register analysis are explicitly presented. Finally, the focus is placed on the justification for the adoption of MD framework and the central methodological steps.

Chapter 4 turns to the specific selection of corpus data, linguistic features and methodological parameters. As the field of WE has received a major boost by its association with corpora (Schreier, Hundt & Schneider, Reference Schreier, Hundt and Schneider2020), the author gives an overview of corpus data, which consist of ten national sub-corpora of the International Corpus of English (ICE) and the global English Twitter corpus. The ICE serves as a basis for quantitative analysis of geographic and register variation. As a supplement to the ICE, the sampling of the custom-made corpus of Twitter messages is fully described in order to model the dimensions of global variation. Additionally, the author illustrates the array of variation features from MD approach, dialectometric analysis and grammatical change analysis and develops the catalog of 236 linguistic features extracted from the combined corpus texts. This chapter concludes with a description of the technical details and parameter settings of exploratory factor analysis (EFA) and a bird's eye view of the resulting space of variation.

Chapters 5 to 7 report on a detailed discussion of register-internal and cross-varietal differentiation in the ten-dimensional space of variation. As these dimensions are divided into three subsets, each of the following chapters makes interpretive sense of the bundles of linguistic variables under one subset. The first three dimensions in Chapter 5 are attributable to general situational parameters relevant to a large number of communicative situations, which distinguish between prototypical written and spoken registers. In order to make the meaning of each dimension tangible, the general discourse properties of these dimensions are demonstrated with the salient linguistics features, the distribution of corpus texts and the sample texts. Accordingly, the pronounced inter-varietal distinctions across modalities are clearly shown in the closing part.

Different from those addressed in the previous discussion, the second subset of dimensions in Chapter 6 is dominated by one very specific register. The dimensions of variation are labeled with separate terms, such as Canonical Narrative Focus and Colloquial Markedness. For each of these, interpretations are presented with the statistic analysis of the notable features, the distributional patterns and the inter-varietal differences. Instead of being attributed to general situational constellations, these dimensions reflect the situational details of individual, highly specific discourse types. More specifically, register-specific dimensions show a narrower level of conventionalization tied to the rules, goals and norms of linguistic activities.

As a complement to the first two subsets, the final set of dimensions in Chapter 7 is less readily subsumed under a logic of a common descriptor or conventions of a narrowly defined register. Based on significantly measured variables and a large corpus database, the remaining four dimensions in the measured feature space are under the separate labels, which are dominated by a complicated distribution across situational registers. The identifiable discourse characteristics of these dimensions are not indicative of a general modality difference or an individual type of register. Moreover, as the final four dimensions are less directly conditioned by the basic situational properties of any given register, this subset focuses more on the strongest variability across varieties of English.

In Chapter 8, the author takes the ten-dimensional space of variation as a whole to elaborate on the research questions of general linguistic similarity and difference. He summarizes the descriptive picture of feature space in the theoretical and statistical analysis of variation, exploring the relationships among different dimensions and teasing apart it in relation to WE literature. Following this logic, the respective influences of register and variety in accounting for linguistic variation are clearly addressed, and a more comprehensive assessment of the descriptive utility is provided with the aid of WE models. This chapter ends with a critical perspective on the explanatory contribution of variety in expounding on the total amount of variation in the corpus data.

In the concluding chapter, the author reiterates the key findings of the research, and revisits the interpretative potential of traditional theoretical models for categorizing the status of English variation. In addition, he re-emphasizes the differential influences of register and variety and puts forward a thought-provoking proposal to the account of relations in linguistic variation. It is suggested that further investigations in the study of global English variation should explore the internal influence and inter-varietal variability between registers and varieties at various levels of granularity (Biber & Conrad, Reference Biber and Conrad2009).

Overall, this book is commendable for three major strengths. First, it is a valuable contribution to the extant literature on the research of English varieties. The author provides a more nuanced dimensional space of linguistic variation and examines the empirical justification of the interpretative power of the overarching theoretical models for different patterns. Second, the novel aggregational approaches contribute to the more systematic and plausible findings. As for the scale of the corpus, this book draws on a large number of individual texts and linguistic features based on the MD method of EFA, which achieves a good balance between quantitative robustness and descriptive nuance. Finally, the common analytical framework for exploring patterns of linguistic variation and the competing role between register and geography might be particularly informative for WE researchers.

Despite the merits of the study mentioned earlier, it is not without drawbacks. The statistical analysis in the research is affected to a certain extent by the absence of spoken American data when comparing the distributions of dimension scores across English varieties. Additionally, although this book concentrates on the description of the fundamental dimensions of linguistic variation, the typical excerpt samples do not seem to be adequate. All in all, it is very likely that this book will become one of the thought-provoking sources for future linguistic variation research.