Research shows many problems and ambiguities of second language acquisition (SLA), which have made learners and readers worldwide unsatisfied. Therefore, this study attempts to highlight theories and research that have comprehensive explanations of the problems and ambiguities of second language acquisition, which learners of English as a Foreign…

In this paper we review Martin Lamb's (2016) publication when motivation research motivates: issues in long-term empirical investigations. We discuss his insightful arguments about the challenges and opportunities related to the engagement with longitudinal research. We begin with a discussion of the concept of context and unpack the complex…

This article enters the debate about the complex and dynamical nature of second language acquisition (SLA) by discussing and commenting on Pallotti's critique of Complex Dynamic Systems Theory (CDST). Pallotti's critique brings to the fore the argument that, due to its anti-reductionist stance, CDST research fails to observe three fundamental…

Learners' self-initiated language learning with mobile technology occurring outside the classroom is often contextualized, heterogeneous, and idiosyncratic. In this study, we propose a time-series clustering methodology for researching informal mobile language learners' learning and development of another language, with a view to unravelling the…

This paper examines evidence for relationships among individual differences (IDs) in L1 achievement, L2 aptitude, and L2 achievement. It begins by providing an overview of my academic journey from L1 educator to L2 researcher and explains the development of the Linguistic Coding Differences Hypothesis (LCDH). Next, I review Peter Skehan's…

The current study responds to the call for increased dialogue among different areas of additional language research. Specifically, we bring together learner corpus research and variationist approaches to second language acquisition to advance learner corpus research in two ways: (a) by modeling interlanguage development and variability and (b) by…

Although classical statistical techniques have been a valuable tool in second language (L2) research, L2 research questions have started to grow beyond those techniques' capabilities, and indeed are often limited by them. Questions about how complex constructs relate to each other or to constituent subskills, about longitudinal development in…

This article introduces two sophisticated statistical modeling techniques that allow researchers to analyze systematicity, individual variation, and nonlinearity in second language (L2) development. Generalized linear mixed-effects models can be used to quantify individual variation and examine systematic effects simultaneously, and generalized…

Usage-based approaches explore how we learn language from our experience of language. Related research thus involves the analysis of the usage from which learners learn and of learner usage as it develops. This program involves considerable data recording, transcription, and analysis, using a variety of corpus and computational techniques, many of…

A number of longitudinal studies of L2 production have reported frequency effects wherein learners' produce more frequent words as a function of time. The current study investigated the spoken output of English L2 learners over a four-month period of time using both native and non-native English speaker frequency norms for both word types and word…

Whilst the links between learner corpus research (LCR) and Second Language Acquisition (SLA) have long been debated, McEnery et al. (2019. "Corpus Linguistics, Learner Corpora, and SLA: Employing Technology to Analyze Language Use." Annual Review of Applied Linguistics 39: 74-92. doi:10.1017/S0267190519000096) claim that learner corpus…

This edited volume offers critical reflections on an essential component of research method in the field of second language acquisition -- data. Scholars working on diverse areas (e.g., pragmatics, corrective feedback, phonology) and approaches (e.g., corpus linguistics, concept-oriented analyses, variationism) have come together to identify…

Drawing on the findings of longitudinal studies in uninstructed contexts over the last two decades, this synthesis explores variations in developmental patterns across second language (L2) pragmatic features. Two synthesis questions were addressed: (a) What are the variations in developmental patterns across pragmatic features?, and (b) What are…

The ability to use language effectively in communication is regarded as important as knowledge of grammatical rules in the communicative competence models. Pragmatic competence, namely the ability to understand and use linguistic forms appropriately according to context, is thus accepted as a vital component of language ability. Recently,…

In bilinguals and second language learners, the native (L1) and nonnative (L2) languages coexist and interact. The L1 influences L2 production via forward transfer, as is seen with foreign accents. However, language transfer is bidirectional: even brief experience with an L2 can affect L1 production, via backward transfer. Here, we review the…