Elen Le Foll’s Textbook English is an impressive and generous contribution to corpus-based research on English register variation and English Language Teaching (ELT) materials. The book offers a detailed account of the kinds of English found in European (German, French, Spanish) secondary school English as a Foreign Language (EFL) textbooks, comparing them to the varieties that learners are likely to hear and read outside the classroom.
Because textbooks can play a central role in shaping language exposure in the early years of instruction, this study addresses long-standing concerns that textbook English differs markedly from everyday use. Instead of isolating features one at a time, Le Foll takes a multivariable approach to model how linguistic features cluster across modes, registers and proficiency levels. Her findings demonstrate that textbook English is not a uniform variety but shows systematic internal variation, contributing to the trend in register studies that have examined the relationship between specific functions within registers to explore intra-register variation (e.g. Biber & Egbert Reference Biber and Egbert2018, Reference Biber and Egbert2023; Biber et al. Reference Biber, Egbert and Keller2020; Biber et al. Reference Biber, Egbert, Keller and Wizner2021). It also complements Goulart’s (Reference Goulart2024) study of undergraduate students’ writing. Such research is helping to connect corpus studies that have traditionally viewed registers as monolithic (e.g. reporting means without examining standard deviations) with approaches that also consider communicative purposes, as in genre-based studies.
The amount of work that went into designing, tagging and analyzing this corpus is extraordinary. Particularly notable is the transparency of her methodological decisions: at every stage, from corpus compilation and variable selection to register tagging and factor interpretation, Le Foll walks readers through the process with clarity and candor. This book will be especially useful to researchers embarking on projects that involve multiple linguistic variables, whether or not they plan to use multi-dimensional analysis (MDA) themselves.
One of the book’s major contributions is the way it uncovers the inner workings of corpus construction. Readers can follow not only what was done but why, and they are given access to tools such as taggers and R packages that they can adapt for their own work. Even corpus linguists who are not interested in MDA per se will find her procedures for corpus creation and register analysis worth studying. Building on the work of Egbert & Staples (Reference Egbert, Staples, Sardinha and Pinto2019), Le Foll explains dimensionality-reduction statistical methods (e.g. exploratory factor analysis (EFA), principal component analysis (PCA)), justifying her methods while also instructing the reader in a way that few other sources have managed. Her attention to functional variation across pedagogical genres is grounded, systematic and explained in a way that invites replication or adaptation.
The structure of the volume offers a strong example of how a dissertation can be adapted for a monograph. Rather than using limited space for an exhaustive review of relevant literature, Le Foll streamlines her discussion while making an abundance of resources available on her website. Although some readers may wish the empirical findings appeared sooner, the payoff is considerable. When Le Foll does turn to the results, the analysis is both nuanced and well supported. Her consistent use of signposting (e.g. ‘Section 5.3.1 begins by outlining the selection of text samples for the present MDAs. This is followed in 5.3.2 by the process of feature selection …’, p. 112) also made it easier to navigate the e-book in a way similar to a physical volume (flipping from one section to another as needed).
Her reflections on the challenges and compromises of MDA in applied settings add depth to the book’s contributions. The style felt, if not conversational, as though the reader was a part of the conversations between research group members. In what follows, I describe the chapters of the book.
Chapter 1 (pp. 1–4) provides a concise overview of the study’s aims, situating the project within the broader field of corpus-based language research and highlighting its relevance for applied linguistics and ELT. Chapter 2 lays out the theoretical and pedagogical motivation for investigating textbook language (‘Context and rationale: Why study textbook English?’, pp. 5–24). Drawing on usage-based theories of language acquisition, input frequency and authenticity in EFL instruction, Le Foll builds a compelling rationale for her focus on textbooks as a major source of linguistic input. The chapter also reviews the role of textbooks in secondary-school foreign language classrooms and identifies gaps in how linguistic input has been assessed.
Chapter 3 (pp. 25–63) offers a comprehensive review of previous approaches to studying textbook language. Le Foll organizes the literature into intra-textbook and comparative methodologies, highlighting how corpus-based techniques have been applied to questions of lexical, grammatical and pragmatic input. Her synthesis of research on features such as multi-word units, modal constructions and pragmatic markers is particularly relevant to contextualize her findings but also valuable to scholars with similar research questions.
Chapter 4 (pp. 64–95) introduces Le Foll’s research aims and research questions. Namely, the study hopes to provide a comprehensive description of textbook English as a distinct variety of English. In pursuing this goal, the project asks how consistent textbook English is and what factors account for variation within and between textbooks. It also considers whether students in France, Germany and Spain are exposed to different types of English input depending on their national context. Another question addresses the extent to which the language of textbooks reflects the ways proficient speakers use English in comparable communicative situations, with attention to whether certain registers are more accurately represented than others. Finally, the study investigates which linguistic features most clearly define textbook English when contrasted with authentic registers, and whether these features remain stable across series or shift depending on proficiency level.
This chapter also describes the Textbook English Corpus (TEC) and the reference corpora used for comparison. Le Foll explains her selection criteria for textbooks, how they were processed and tagged, and how she created corpora representing spoken, fictional and informative English aimed at teens. The detail with which she documents these decisions is striking. Her Open Science statement and rationale for choosing particular corpora reflect a strong commitment to methodological rigor and reproducibility.
Another feature of chapter 4 is that it outlines how Le Foll divided her corpus into registers: conversation, fiction, informative, instructional and personal correspondence. The process was interesting enough for a book-length treatment and will appeal to materials developers. It was also central to her research questions, because it allowed her to examine how these communicative purposes differ linguistically and to compare them to non-textbook corpora of similar registers.
The methodological heart of the book comes in chapter 5 (pp. 96–139). Here, Le Foll describes how she adapted and expanded Biber’s MDA framework to suit her data, explaining each step from feature selection and normalization to factor analysis and dimension score comparisons. Her discussion is technical but accessible, with visualizations that clarify how the adapted MDA works in practice. The level of detail makes this chapter especially important for methodologically oriented readers. As Le Foll notes, replicability is a challenge in MDA research (p. 139), and her explicit description of her rationale, as well as the transparency of her code and tag counts, will help remove some of those barriers.
Chapter 6, titled ‘A model of intra-textbook linguistic variation’ (pp. 140–66), marks the beginning of the book’s empirical findings and reports on the first MDA model, which is used to examine variation within the TEC. Le Foll identifies four major dimensions of variation: (1) overt instructions and explanations, which capture explicit directive and metalinguistic content; (2) involved versus informational production, contrasting interactive and interpersonal language with more expository styles; (3) narrative versus factual discourse, which reflects the balance between storytelling and factual reporting; and (4) informational compression versus elaboration, highlighting the degree of detail and expansion within the text. Each dimension is presented with quantitative results, interpretive commentary and text excerpts from the corpus that exemplify the high and low ends of the scale.
Le Foll takes care to explain how these dimensions emerged from the statistical analysis, noting which linguistic features loaded most strongly on each factor and what communicative functions they likely serve in the textbook context. She also examines how these dimensions vary across the registers identified in chapter 4 (conversation, fiction, informative, instructional, personal correspondence), showing that the textbooks do not treat each register as a homogeneous whole but distribute features in ways that reflect particular pedagogical goals. The chapter includes visualizations, such as dimension score plots, that allow readers to see how registers cluster or diverge in the multi-dimensional space. Not only are the visualizations helpful to understand this study, I imagine that scholars interested in doing similar work will be inspired by the ways that Le Foll displays such complex quantitative results. This level of methodological and interpretive detail provides a strong foundation for the comparative work in later chapters.
The analysis is extended for chapter 7 (pp. 167–94), which shows how the TEC registers compare to corresponding registers in the reference corpora (representing ‘real-world’ language use by and for teens in conversation, fiction and informational contexts). The comparative MDA approach allows Le Foll to examine alignment and divergence between textbook language and its intended real-world targets. The findings reveal consistent gaps: for example, textbook conversations tend to omit key interactional features such as discourse markers, interruptions and non-minimal responses, resulting in a more scripted and less spontaneous feel. In fictional registers, textbooks often simplify narrative structures, avoid certain colloquial expressions, and reduce variability in tense and aspect compared to authentic teen fiction. Informative registers show a tendency toward simplification and controlled vocabulary, which may benefit learners at certain proficiency levels but fails to capture the lexical density and syntactic complexity of real-world informational texts.
Le Foll interprets these divergences in light of pedagogical constraints, editorial norms and assumptions about learner needs. She does not simply present a deficit view of textbook language; rather, she considers how these differences might be deliberate choices to scaffold comprehension or manage cognitive load. Nevertheless, the comparisons make clear that textbooks sometimes underrepresent features that are crucial for communicative competence, particularly in spoken interaction. The chapter’s careful balance between critique and explanation provides a nuanced account of authenticity and appropriateness in pedagogical materials.
In chapter 8 (‘Discussion: What is Textbook English?’, pp. 195–203), Le Foll synthesizes findings across the two MDA models to address her four research questions directly. She summarizes how textbook English exhibits systematic internal variation, with distinct profiles for different registers, and how these profiles compare to authentic registers in the reference corpora. The synthesis underscores that textbook English is neither a monolithic nor an arbitrary construct; it is shaped by a combination of pedagogical aims, curricular requirements and institutional conventions.
Le Foll discusses the degree to which each register aligns with its authentic counterpart, identifying areas where textbooks are reasonably representative (such as certain aspects of instructional and informative writing) and areas where representation is uneven or incomplete (notably conversational language). She also considers the potential consequences for learners: for instance, limited exposure to authentic conversational features may hinder the development of interactional competence, while underrepresentation of certain narrative structures could affect literacy development. The chapter also reflects on how the adapted MDA framework facilitated this level of analysis, highlighting the value of modeling intra-register variation rather than treating each register as a single point of comparison.
Chapter 9 (pp. 204–36) focuses on the pedagogical applications of the research, translating the corpus findings into practical implications for textbook authors, publishers and teachers. Le Foll proposes strategies for supplementing textbook materials to better reflect the linguistic realities of the target registers. This includes integrating authentic conversational extracts with features such as turn overlaps, backchannels and pragmatic markers; expanding the range of narrative styles and voices in fictional texts; and increasing lexical and syntactic diversity in informative writing. She also addresses how corpus findings can inform decisions about sequencing, scaffolding and balancing exposure to multiple registers.
Importantly, Le Foll emphasizes that aligning textbooks more closely with authentic language does not mean abandoning the pedagogical simplifications that make them accessible to learners. Instead, she advocates for informed adjustments that preserve comprehensibility while incrementally introducing underrepresented features. The chapter includes examples of how such adjustments might look in practice and discusses how teacher mediation can bridge the gap between simplified input and authentic target language use. This makes the chapter useful not only for material developers but also for classroom practitioners seeking to enrich their use of existing textbooks.
As noted above, this book is a wealth of methodological insight. Chapter 10 (pp. 237–44) returns to methodological considerations, reflecting on the challenges and decisions involved in adapting MDA for textbook data. Le Foll discusses issues of factor interpretability, the influence of corpus design on results and the complexities of selecting appropriate reference corpora. She notes that while MDA offers powerful tools for uncovering patterns of co-occurring linguistic features, its outcomes depend heavily on careful variable selection, normalization and interpretation. By making her data, code and tagging procedures available, she addresses one of the persistent criticisms of MDA research: the difficulty of replication.
This chapter also situates her methodological contributions within the broader field, suggesting how the adapted framework could be applied to other corpora, whether in educational contexts or beyond. Le Foll reflects on how transparency, open access and methodological rigor can support cumulative research in corpus linguistics. For readers interested in both the ‘what’ and the ‘how’ of corpus-based analysis, this chapter reinforces the book’s dual value as a substantive contribution to knowledge about textbook English and as a model for designing and reporting complex corpus studies.
Chapter 11 (pp. 245–51), the last chapter, revisits the book’s major findings and reiterates the importance of examining textbook English as a register in its own right, rather than treating it as a homogeneous variety. Le Foll also gestures toward future directions for research, including studies of learner uptake and the development of improved pedagogical materials.
As a final observation, I found Textbook English to be a significant and generous scholarly offering. It will serve both researchers and educators, and I expect it to be cited often for its findings and methodological innovations. The combination of a rigorously compiled, openly documented corpus with a carefully adapted MDA framework makes it an important resource for corpus linguistics, applied linguistics, educational linguistics and English language teaching.
