Now in its second edition, this handbook is a current overview of second language (L2) research, providing state-of-the-art synopses of recent developments in each subarea of the field and bringing together contributions by emerging scholars and experts in second language acquisition (SLA). Since the first edition, broad sociopolitical movements, alternative views of bilingualism, emergence of global markets, vast expansion of electronic resources, the development of social media and the availability of big data have transformed the discipline, and this edition has been thoroughly updated to address these changes. It is divided into six main parts: Part I situates SLA in terms of research and practice; Part II explores individual cognitive, age-related and neurolinguistic similarities and differences; Part III outlines external, sociocultural and interactive factors; Part IV presents profiles of bilinguals who take differing paths of acquisition; Part V describes interlanguage properties; and Part VI comprises clear models of L2 development.

The chapter provides an introduction to the sociocultural analysis of second language (L2) acquisition as a process of socialization by and through the learning of an additional language. It offers a discussion of socio-cultural institutions and communities involved in L2 learning as well as a description of the development of language repertoire in additional language learning as a social accomplishment. The chapter opens on a summary of the controversy that arose in the early 2000s between the cognitive and the socially-oriented Second Language Acquisition (SLA) paradigms. Bypassing this divisive debate, the chapter focusses on the diversity of approaches to additional language learning within the sociocultural paradigm. Key concepts of sociocultural SLA research such as social integration, agency, identity and power relations as well as affordance and language repertoire are defined. A framework of analysis for the learner’s language repertoire is presented. Finally, the chapter recalls issues in the study of naturalistic SLA as a privileged area of research in light of the sociocultural paradigm. Longitudinal data from one migrant worker are analysed to illustrate the social and linguistic development of his language repertoire. In conclusion, the chapter charts some pending issues for the sociocultural analysis of L2 socialization.

A survey of language variation (phonological, lexical, grammatical, and pragmatic) - includes regional, generational, and gender variation. Covers the difference between languages and language varieties, kinds of variation (regional, socioeconomic, gender, age, vocational), phonological variation, lexical varation, grammatical variation, and discourse and stylistic variation.

In this chapter, we provide an overview of how second languages (L2s) are acquired, processed and represented in the brain. We begin by reviewing experimental methods, along with relevant studies employing them, with a particular focus on fMRI and EEG, two metabolic and electrophysiological measures that elucidate our knowledge of multiple languages in one brain. We then discuss a few moderating effects of L2 acquisition along with a dialogue of how multilinguals process structure and meaning as elaborated in key theories. Finally, we elaborate on how research on multiple memory systems can possibly shed light on the acquisition and teaching of L2s in the classroom with respect to the effectiveness of the explicit presentation of grammar rules and feedback. We conclude by identifying research topics that are shaping ongoing work in bilingual processing and sparking new dialogues that have the potential to significantly advance the field.

In this chapter, we present and discuss the contributions that usage-based theories of language have made to the theory and practice of second language learning and teaching. Soon after its establishment as an independent theoretical framework, usage-based linguistics inaugurated an applied branch with two volumes by Pütz et al. dedicated to second language acquisition (SLA) and language pedagogy (LP). Rather unusually, usage-based theories retained a close link between linguistic theory, the theoretical study of language acquisition and the development of language pedagogy, resulting in a number of direct applications of usage-based linguistic insights to the study of language learning and teaching.Because of the crucial role that cognitive capacities play in usage-based approaches they are naturally amenable to the integration of insights from psychology. We will zoom in on a particularly fruitful line of research that has seen insights from the psychology of learning applied to language across L1 and in L2. Looking ahead, we discus work that puts learning models from psychology to use for the operationalisation of the usage-based notion of emergence, thereby challenging traditional assumptions regarding the mental representations of language attributed to language learners by linguists and how these apply to the theory and practice of L2 learning and teaching.

This chapter addresses the nature of the semantic component and its role in the second language (L2) acquisition of meaning, considering a range of properties: quantification, polarity items, articles, clefted interrogatives and referential dependency relations. It discusses guidance by preexisting conceptual components including conceptual representations and inferential processes, such as scalar inferences, in various form-meaning mappings such as lexical selection and structural interpretation. It connects L2 semantic development with first language (L1) transfer, Universal Grammar-guidance overcoming poverty of the stimulus, as well as feature reassembly in developing new lexico-grammatical representations for the L2. It highlights the role of activation thresholds for developing neurofunctional subsystems mapping syntax-semantic features to forms in L2 input processing. An L2 neurofunctional subsystem overlapping with the L1 system accounts for micro-level L1 effects together with guided L2 semantic development. The chapter thus overviews the findings of L2 semantic research suggestive of guidance by an implicit neurofunctional system for the L2. It addresses both robustness and vulnerability in aspects of L2 interpretation and highlights the vital role played by the conceptual structure component and aspects of memory in many aspects of L2 interpretive behavior.

In the previous chapter we looked at how we use and understand language, now let’s look at the ways that people lose language and also experience language difficulties of various kinds. These aren’t the normal errors and mistakes we’ve already discussed, but are the result of disability, disease, disorder, brain injury, and other factors that can affect speech use and understanding and further impair the ability to read and write. In the US alone, between five to ten percent of the population have various types of communication disorders. The figures are even higher for learning disorders such as dyslexia. All in all, this amounts to millions of people who live with language differences. This chapter discusses how both developmental and acquired disorders affect language processing and production.

This chapter begins with a brief overview of the historical connections between the fields of second language acquisition (SLA) and computer-assisted language learning (CALL). We trace the development of this field from its primarily cognitive origins to the social turn in the early 2000s and to the affective turn, with its more recent emphasis on the learner and teacher’s psychology. The latter has led to an increased recognition of the roles of individual learner differences in second and foreign language learning and the investigation of technology on learners’ motivation, emotions and self-regulation of learning both inside and outside of the classroom. The complex interaction between learner-internal and -external factors (including the mediating role of technology) has led to a view of language acquisition as a complex dynamic process, and this is increasingly evident in research on technology-mediated learning. In our synthesis, we classify recent developments into four distinctive, yet interrelated strands: technological developments, theoretical and conceptual developments, pedagogical developments, and methodological developments. In particular, we illustrate these developments with examples of technological and pedagogical innovations used for language learning such as Language MOOCs, augmented and virtual reality, big data, learning analytics and artificial intelligence.

Heritage language speakers are second language (L2) speakers of a sociopolitically majority language. Their native heritage language is a minority language which typically develops under linguistic pressure from the majority L2 and eventually becomes secondary and weaker than the L2. In the past decade, research on heritage language speakers has investigated the degree of acquisition of different aspects of the heritage grammar and how the process and outcome of heritage language acquisition are similar to and different from adult L2 acquisition. Advances in the acquisition of heritage languages have contributed significantly to inform key questions in L2 acquisition. This chapter discusses the latest research on how L2 learners’ and heritage speakers’ exposure and use of the L2 and L1 affect the processing and acquisition the L2 and the heritage language and points to areas in need of further research.

Earlier studies of maturation effects and ultimate achievement – UA, eventual knowledge of a second language (L2) – mainly involved immigrants to English-speaking countries tested on the native-likeness (how much they sounded like native speakers) of their L2 phonology or morphosyntax. In these classic studies, a consistent finding was that perceived native-likeness inversely correlated with increasing age of onset of acquisition (AoA), a finding linked to an optimal period for SLA. The past decade has developed new perspectives on these issues, eschewing the notion of native-likeness as a gold standard, incorporating numerous factors in addition to AoA and looking at the interaction of the two languages of the bilingual. Factors include environment of acquisition, input and individual learner characteristics. This chapter outlines the classic studies of AoA and the Critical Period Hypothesis (CPH) before turning to UA in phonology, morphosyntax and processing. It then reevaluates the term native speaker, a label that has received criticism for perpetuating Eurocentric models; it finally recapitulates several components that can be taken into account to explain the range of ultimate achievement in child and adult L2.

Working memory (WM), our ability to hold a small amount of information readily available for ongoing use, is crucial to language processing. This chapter examines verbal WM models/tests and then covers WM effects on bilingualism, noting mixed findings for L2 comprehension, production, vocabulary, grammar and morphosyntax. These inconclusive findings are due to: (a) WM tests (stronger effects in linguistic than nonlinguistic, oral than written, L1 than L2 tests); (b) cognitive load of the WM test and experimental task (stronger effects in more than less complex tasks); and (c) L2 experience (stronger WM effects in learners with lower than higher L2 proficiency and use). The following sections delve into bilingualism effects on WM, considering the debates on whether WM is trainable directly (practice) or indirectly (simultaneous interpreting) and whether bilinguals have greater WM than monolinguals; it shows nondetrimental effects of being bilingual on atypically developing populations with WM deficits. A final section proposes L2 instructional practices to increase attention to inflectional morphology and compensate for WM shortcomings. Finally, it considers how the field might evolve.

This chapter will introduce the reader to the study of third (L3) or further (Ln) acquisition. The circumstances surrounding the acquisition of language beyond the second conspire to make this a unique context, distinct from L2 acquisition. The L3 learner has at least partial knowledge of more than one grammar, previous experience with nonnative language learning and, in most cases, at least some metalinguistic knowledge. All these factors significantly condition both the starting point and the trajectory of L3/Ln language acquisition in ways that cannot be predicted from our understanding of L1 and L2 acquisition and reflect qualitative as well as quantitative changes in going from two to three or more languages. In this chapter, the reader will find an introduction to the basic concepts and themes of L3/Ln acquisition research, an overview of L3/Ln theories from a cognitive perspective – modeling the acquisition of both morphosyntax and phonology – an in-depth discussion of the role of previously acquired languages, and a brief introduction to some of the most recent work on L3 processing, including studies using electroencephalography (EEG) and semiartificial languages to address long-standing questions in the field while overcoming some of the most common methodological and logistic issues facing the L3/Ln researcher.

Vygotsky introduced the Zone of Proximal Development (ZPD) in the 1930’s. ZPD activity involves semiotic mediation of mind and is a unit of analysis in sociocultural theory (SCT) and activity theory. ZPD activity reveals a learner’s potential future development. Higher cognitive development, including second language acquisition (SLA), involves social processes as learning-leads-development in ZPD activity, where developmentally appropriate support (from other persons or from semiotic tools) enables functioning beyond a learner’s independent skills. Too much support, beyond a learner’s ability to understand, is outside of the ZPD and does not reveal developmental trajectories. Early L2 research on ZPD activity focused on identifying ZPDs using discourse analytic approaches. Promoting ZPD activity is at the core of concept-based language instruction (C-BLI) and dynamic assessment (DA), two interventionist pedagogical approaches. Process-oriented research most effectively reveals ZPD activity. Instead of mentioning ZPD activity, SCT researchers may discuss mediation; ZPDs may also be evident in non-SCT process-oriented studies. Examples of research relevant to ZPD activity include work focused on identifying and understanding ZPD activity, studies on explicit instruction (C-BLI) and instructional assessment (DA), and process-oriented studies on interaction between people and other persons or semiotic tools, including digital tools.

A survey of phrase and sentence grammar, including discussion of the difference between grammaticality and acceptability, parts of speech-word classes, word order, case marking, verbal inflection, constituency, structural ambiguity, argument structure, anaphora, quantifiers, and negation.

An introduction to phonetics and phonology, including discussion of the difference between letters and sounds, an introduction to IPA, articulatory and acoustic phonetics, phonemics and the psychological reality of phonemes, production vs. comprehension and phonemic processes, and phonological word play (spoonerisms, malapropisms, and modegreens).

Lexis is central to language acquisition, as knowing a sufficient number of words is crucial for effective communication. For instance, 98 per cent word familiarity is necessary to comprehend written texts. Fewer words may suffice for speech comprehension, though variation among learners is significant. This chapter examines how vocabulary influences foreign language acquisition, reviewing key findings and recent developments in the field. First, achieving proficiency requires mastering at least 2,000-word families in English. Second, this threshold varies by task and learning environment. Third, corpus studies show that there are some words that cover a large proportion of all words occurring in spoken and written texts and that they tend to cluster together in various categories of formulaic language, which may make up to a half of discourse. Fourth, deliberate and incidental learning are complementary, though explicit instruction accelerates vocabulary acquisition in instructional settings. Finally, this chapter considers how educators can integrate classroom teaching with extramural learning. Evidence is continuing to emerge that extramural activities such as watching TV, listening to songs, gaming and engaging in social media may be promising avenues for learning words . However, it is unclear exactly how much vocabulary is acquired in extramural settings, and there is a need for future research to focus more on the systematic investigation of extramural learning environments, across a range of languages and for different age-groups.