Research on English as a lingua franca (henceforth ELF) has rapidly grown into a ‘vast, widely known and largely accepted research field’ (p. 1). As the first ELF handbook, the book under review provides readers with a comprehensive overview of this newly emerged area of research by covering its concepts, theories, research findings and applications with 47 chapters distributed within seven major parts. The chapters in each section are interrelated but independent to some degree and therefore they allow readers to start with any chapter according to their interest.

The opening part of the book, Conceptualising and positioning ELF, introduces related concepts, theories, and perspectives within the field of ELF research. Thus, it serves as a theoretical foundation for the whole handbook. The eight chapters in this section are contributed by leading researchers from ELF and other highly relevant areas of linguistics. Mauranen reconceptualises ELF with a three-pronged approach, consisting of three intertwined perspectives, namely the macro-social, the meso-social and the micro-cognitive, in an integrated manner. Focusing on the intercultural nature of ELF, Baker examines the potential for productive inter-fertilization between intercultural communication and ELF research by adopting post-structural perspectives to central concepts, including culture, community and identity. Ehrenreich explores the possibilities of conducting empirical research on ELF in business contexts by adopting Wenger's (Reference Wenger1998) concept of community of practice. Drawing on Complexity Theory as a metatheory, Larsen-Freeman views ELF as a complex adoptive system composed of multiple nested levels of ‘individual human beings, their contacts zones, and globalized networks’ (p. 54) and challenges the privileged English native speaker norms. Leung and Lewkowicz re-examine communicative language teaching practices in English language teaching within Jenkins’ (Reference Jenkins2015) expanded conceptual framework of ELF. Viewing ELF as ‘a communicative mode or situation’, Hall investigates the cognitive resources and processes underlying ELF interactions with a focus on the distinctive nature of ‘the processing of English in interactions between heterolinguals’ (p. 74). Seidlhofer's contribution reveals the dynamic nature of ELF communication by scrutinizing the basic assumptions about Standard English in terms of language ideology. Considering ELF as adaptive variation of English, Widdowson examines the pragmatic mechanism underlying the development of ELF from a historical perspective.

The second part, The regional spread of ELF, deals with the use of ELF in various geographical regions. Sherman summarizes the current situation of ELF in Europe by viewing ELF as a strategic resolution to communicative and sociocultural problems. With a focus on BELF, Alharbi presents a systematic account of ELF use and attitudes in the Gulf Cooperation Council states. Kirkpatrick proposes six pedagogic principles for a lingua franca approach to English language teaching (ELT) based on his analysis of the nature of ASEAN ELF. Based on questionnaire responses and interviews, Wang investigates Chinese English speakers’ perspectives on ELF within Anderson's (Reference Anderson2006) framework of imagined communities. D'Angelo surveys the rising status of ELF in Japan by focusing on institutional ELF promotion efforts. Similarly, Gimenez, El Kadri and Calvo picture the present situation of ELF in academic circles in Brazil from both national and regional perspectives. Finally, van der Walt and Evans examine the prominent status of English as an intra-national lingua franca in South Africa.

The third part, ELF characteristics and processes, covers a variety of topics concerning the linguistic features of ELF and ELF interaction. Osimk-Teasdale suggests a dual tagging system for describing and analyzing variability in ELF data based on her corpus tagging experience. From a diachronic point of view, Cogo and House review research into pragmatic aspects of ELF interaction in a comprehensive way. Adopting a corpus-based approach, Ishamina and Deterding investigate how simplification and substitution of initial consonant clusters affect intelligibility in ELF conversations. Based on data from the Vienna-Oxford International Corpus of English, Pitzl explores how and why ELF speakers create idioms and metaphors in ELF interactions. With a focus on ELF grammar, Ranta reflects on present studies of non-standard features of ELF and proposes a series of topics for more in-depth investigation. Considering similarities between ELF and other varieties of English as morphosyntactic features, Bjökman revisits the construct of variety and argues that it is not reliable for ELF. After reviewing research on language norms and ELF normativity, Hynninen and Solin examine how ELF norms are created, maintained and negotiated in academic contexts from the perspective of language regulation. To fill the gap in ELF communication research, Jenks investigates how uncooperative interactions unfold in different ELF contexts by adopting Antaki's (Reference Antaki2011) applied conversation analysis.

The fourth part, Contemporary domains and functions, consists of chapters focusing on ELF in various domains and from different perspectives. Kimura and Canagarajah examine the similarities and differences between ELF research and translingual practice studies in terms of theoretical basis and research focuses. Drawing on Wenger's (Reference Wenger1998) concept of community of practice, Kankaanranta and Louhiala-Salminen explore BELF users’ perceptions of business knowledge with data from an online questionnaire survey and 15 email interviews. As for ELF within the private social sphere, Pietikäinen reports on her investigation into multilingual language identity in established intercultural relationships, after reviewing studies of multilingual practices in social ELF and on miscommunication-avoiding strategies employed by ELF couples. With a focus on humor and relational work in ELF, Pullin analyses various interpersonal functions of ELF humor in both academic and corporate settings. After introducing the concept of electronically mediated intercultural communication (EMIC), Sangiamchit examines the relation between EMIC on social network sites and intercultural ELF usage. Highlighting the multilingual nature of ELF communication, Cogo provides a critical overview of studies on multilingualism in ELF from two intertwined perspectives of code-switching and translanguaging. This section concludes with Albl-Mikasa's review of research in the subfield of ITELF (interpreting, translating and ELF) focusing on ELF's impact on interpreting and translating and ITELF research's influence upon ELF.

The fifth part, ELF in academia, focuses on ELF in university settings. To ‘foreground the multilingual aspect of higher education’ (p. 387), Smit explores academic ELF in higher education institutions from the perspective of language policy. Calling for a critical appraisal of English-medium instruction in higher education in Japan, Murata and Iino report on their survey on the English-medium instruction courses at a Japanese university from the perspective of ELF. With a holistic approach, Horner critically examines the newly-emerged research area of written academic ELF and proposes several future research directions. Wingate investigates the transformation of language and literacy policies in UK universities from the perspective of multilingualism and claims that the ELF principle of mutual intelligibility offers the most realistic orientation.

The sixth part, ELF, policy and pedagogy, will be of particular interest to those involved in ELT and teacher education. Dewey and Patsko explore the incorporation of an ELF perspective into language teacher education by focusing on initial teaching awards for novice teachers and experienced practitioners in the UK. To raise teachers’ ELF awareness, Sifakis and Bayyurt present a three-phrase framework of ELF-aware teacher education based on a concept of ELF-aware teacher learning and development. Drawing on McDonough, Shaw & Masuhara's (Reference McDonough, Shaw and Masuhara2013) three-stage process of evaluation and Tomlinson's (Reference Tomlinson and Harwood2010) checklist for materials, Galloway investigates how ELT materials might be designed and evaluated for ELF contexts. Hüttner discusses ELF's impacts on Content and Language Integrated Learning in terms of language management, language beliefs and language practices at language policy level. Focusing on ELF-compatible developments, Suzuki, Liu and Yu review local ELT in three Asian contexts: Japan, China, and Taiwan. Wright and Zheng analyze the difficulties of integrating ELF into ELT with reference to the contrasting theoretical approaches to language: language as system versus language as dialogic creativity. From an English language teachers’ perspective, Llurda examines the evolutionary impacts of ELF research on non-native English speaking teachers based on related studies.

The final part, ELF into the future: Trends, debates, predictions, explores future research areas for ELF on the basis of a number of trends and debates. Considering current conceptualizations of ELF practices, Baird and Baird propose new approaches to reframe ELF perceptions based on their critical review of ELF attitude research. Guido investigates ELF miscommunication in migration contexts and emphasizes the transfer of first language cognitive-syntactic structures as the underlying cause. Focusing on the theoretical shift in ELF research, Morán Panero critically reviews studies concerning global languages and ELF and argues that the integration of a clear ontology of language boundaries into research of English as a multilingual franca is a major challenge. Considering the communicative competence debates, Harding and McNamara analyze the challenges of ELF for language assessment and discuss possible approaches to overcome those difficulties. In contrast, Shohamy explores ELF assessment within Shohamy's (Reference Shohamy2001) framework of critical language testing and offers initial proposals for language assessment practices related to ELF. Finally, Jenkins describes the evolution of ELF research and predicts its future developments.

With such a wide-ranging and state-of-the-art collection of chapters, this handbook, as a whole, is a comprehensive and authoritative exploration of the rapidly developing field of ELF research. It covers the key concepts, theories, domains, applications and future trends of ELF studies. Nearly all of the theoretical perspectives employed in ELF research have been presented in the handbook, including language pedagogy (e.g. Leung & Lewkowicz; Wright & Zheng), intercultural communication (e.g. Baker; Sangiamchit), Complexity Theory (Larsen-Freeman), pragmatics (e.g. Widdowson; Pietikäinen), language ideology (e.g. Seidlhofer; Baird & Baird), language assessment (e.g. Harding & McNamara; Shohamy) and multilingualism (e.g. Panero; Jenkins). On the other hand, it consists of well written and enlightening chapters composed by leading international scholars in ELF and other related areas, such as Mauranen, Jenkins, and Widdowson. Additionally, the handbook is well-structured and easily accessible. All contributions are written in an accessible and concise style and each chapter is organized in a similar order. All chapters are independent but intertwined although they are grouped into seven parts. All these merits make this handbook an important and valuable reference work for graduate students, academic researchers and ELT practitioners, who are engaged in the study of ELF, global Englishes or language education.

However, this handbook is not without weaknesses. Firstly, ELF in business and ELF use in higher education have been more extensively studied than ELF in any other domains (Jenkins, Cogo & Dewey, Reference Jenkins, Cogo and Dewey2011), but the former is almost ignored while the latter has been greatly stressed in this handbook. Secondly, some chapters composed by contributors who do not focus on ELF research seem to be less informative and innovative than others (e.g. Albl-Mikasa; Suzuki, Liu & Yu; Murata & Iino).