As part of ongoing efforts to characterize the extent to which tasks and interaction-driven language learning are influenced by individual differences (IDs), task-based researchers have thus far examined variables like learners’ levels of L2 anxiety, motivation, cognitive creativity, working memory capacity, and aptitude. Building on a tradition of prior syntheses in task-based language teaching (TBLT, e.g., Plonsky & Kim, 2016), we carried out a methodological review of the practices used by researchers who have examined learners’ IDs in task-based language learning. We searched journal articles published between 2000 and 2023 and identified 135 unique samples for analysis. Each empirical study was coded for relevant contextual and demographic variables as well as for methodological features related to the investigation of individual differences. We observed that of 30 individual differences investigated in TBLT research over the last two decades, the top five most common were motivation, working memory, L2 proficiency, anxiety, and aptitude. Interesting patterns related to operationalizations, instruments, coding, analyses, and reporting practices. In this paper, we report these results and summarize the most and least common methodological practices, also pointing out gaps and possibilities for future directions. We conclude with recommendations for researchers interested in embarking on empirical investigations of individual differences and TBLT based on best practices.

The use of connectives has been considered important for assessing the cohesion of written texts (Crossley et al., 2019). However, existing connective-based indices have not systematically addressed two issues of ambiguity, namely, that between discourse and non-discourse use of polysemous word forms and that in terms of the specific discourse relations marked by polysemous discourse connectives (Pitler & Nenkova, 2009). This study proposes 34 sense-aware connective-based indices of cohesion that account for these issues and assesses their predictive power for cohesion ratings in comparison to 25 existing indices. Results from the analysis of 3,911 argumentative essays from the English Language Learner Insight, Proficiency and Skills Evaluation Corpus show that 23 sense-aware indices but only three existing indices correlated significantly and meaningfully with cohesion ratings. The sense-aware indices also exhibited greater predictive power for cohesion ratings than existing indices. The implications of our findings for future cohesion research are discussed.

This study investigates the effects of retrieval schedules on the acquisition of second language (L2) collocations. Chinese learners of English first studied 36 target verb-noun collocations using flashcards and form-meaning matching practice. Subsequently, the participants practiced retrieving the target collocations from memory, following either a massed (consecutive) or spaced schedule. After each retrieval attempt, corrective feedback was provided. The acquisition of L2 collocations was measured by near-immediate and 1-week delayed posttests that assessed explicit knowledge with an offline form recall task, automatized explicit knowledge using an online acceptability judgment task, and implicit knowledge with an online collocation priming (lexical decision) task. Results showed equal learning effects of massed and spaced retrieval at both posttests of explicit knowledge and the near-immediate posttest of automatized explicit knowledge. The spacing effect was observed for the implicit knowledge across the two posttests and the automatized explicit knowledge at the delayed posttest.

To test the contributions of processing to L2 syntax learning, this study explores (cross-) linguistic and cognitive predictors of sentence reanalysis in the L2 comprehension of relative clauses among low-intermediate L1 German adolescent learners of L2 English. Specifically, we test the degree to which L2 comprehension is affected by L2 proficiency, reanalysis ability in a related, earlier-acquired L2 structure (questions), reanalysis ability of relative clauses in the L1, cognitive control, and cognitive capacity. In visual-world eye-tracking experiments, 141 adolescent German-speaking L2 learners of English selected target pictures for auditorily presented questions and relative clauses in the L1 and in the L2. The results showed a strong subject preference for L2 relative clauses. Learners’ L2 proficiency and their processing of object questions in the L2 predicted reanalysis for object relatives in eye movements, reaction times, and comprehension accuracy. In contrast, there was no evidence that cognitive control or working memory systematically affected the processing of object relatives. These findings suggest that linguistic processing outweighs cognitive processing in accounting for individual differences in low-intermediate L2 acquisition of complex grammar. Specifically, learners recruit shared processing mechanisms and routines across grammatical structures to pave a way in the acquisition of syntax.

We present a learner corpus-based study of English article use (“a”/“the”/Ø) by L2 learners with four typologically distinct first languages (L1s): German and Brazilian Portuguese (both have articles), Chinese and Russian (no articles). We investigate several semantic and morphosyntactic factors—for example, specificity, prenominal modification that can affect article use. Our analysis of 660 written scripts from the Education First Cambridge Open Database confirms the lower overall accuracy of learners with no-article L1s. Our main finding is the differential effect of specificity on definite and indefinite articles: learners tend to associate specificity with “a,” which implies article omission with nonspecific indefinite singulars and overuse of “a” with specific indefinite mass nouns. Prenominal modifiers further contribute to perceived specificity, leading to article overuse with modified indefinite mass nouns. However, in definite contexts, prenominal modifiers are associated with increased article omission.

The present study uses self-paced reading as a measure of online processing and an acceptability judgement task as a measure of offline explicit linguistic knowledge, to understand L2 learners’ comprehension processes and their awareness of subtle differences between the modal auxiliaries may and can. Participants were two groups of university students: 42 native speakers of English and 41 native speakers of Croatian majoring in L2 English. The study is part of a larger project that has provided empirical evidence of the two modals, may and can, being mutually exclusive when denoting ability (can) and epistemic possibility (may) but equally acceptable in pragmatic choices expressing permission. The present results revealed that L1 and L2 speakers rated the acceptability of sentences in offline tasks similarly; however, L2 learners showed no sensitivity to verb–context mismatches in epistemic modality while demonstrating sensitivity when processing modals expressing ability. Implications for L2 acquisition of modals and future research are discussed.

This study examined the effects of distributed practice on second language (L2) speech fluency development. A total of 116 Japanese L2 learners of English were randomly divided into experimental or control conditions. Learners assigned to the experimental groups engaged in four fluency training sessions either in a short-spaced (1-day interval) or long-spaced (7-day interval) condition. Although different learning trajectories were observed during the training phase, the posttests conducted 7 and 28 days after the training showed similar fluency gains for the two groups, indicating that short- and long-spaced conditions were equally effective for developing L2 fluency. The current study extends the line of research in distributed practice and task repetition for L2 fluency development.

This study examined the role of discourse organization in second language (L2) comprehensibility ratings. Twelve English for Academic Purposes teachers listened to 60 L2 speech samples elicited through a TOEFL–type integrated speaking task, evaluating each sample for comprehensibility and coherence (perceived interconnectedness of ideas). The samples were analyzed for the occurrence of discourse features at micro and macro levels. Results revealed a strong association between coherence and comprehensibility (r = .70). Whereas L2 speakers’ use of additive connectives (e.g., and) uniquely predicted comprehensibility, ordering of ideas and source–speech similarity in speakers’ performances predicted coherence. Lexical overlaps predicted both constructs. Findings underscore the importance of coherence to comprehensible academic L2 speech demonstrating that the two constructs include partially overlapping yet distinct characteristics.

Most words in a language have more than one meaning. Yet, few studies have explicitly examined the acquisition of secondary meanings of L2 words and the extent to which polysemy and homonymy affect vocabulary learning. This study explores the effect of polysemy and homonymy on the deliberate acquisition of the form–meaning connections of L2 words. Thirty-six EFL learners (compared with a control group of 30) learned secondary polysemous and homonymous meanings of familiar words and primary meanings of unfamiliar words using flashcards. Knowledge of target words was measured using meaning–recall and meaning–recognition tests immediately after the treatment and again one week later. The findings indicated that learning another meaning for a familiar word was just as difficult as learning the primary meaning of an unfamiliar word, suggesting that the type of meaning (primary, secondary polysemous, or secondary homonymous) might not be an influencing factor in the deliberate acquisition of L2 words.

This study investigates whether second language (L2) learners’ language development and accuracy in production are comparable across oral and written modalities on the basis of Pienemann’s processability theory (PT). Eighty-seven English as a Foreign Language (EFL) learners, from high beginner to advanced levels, completed comparable speaking and writing tasks designed to elicit particular morphosyntactic structures predicted by PT to correspond to L2 stages of development. Time constraints encouraged participants to respond spontaneously, thus drawing on implicit knowledge. Implicational scaling shows correlations that suggest comparable language development between the modalities. However, accuracy was higher earlier in the written than in the oral modality, and accuracy in the written modality was more stable. The results provide a clearer understanding of the similarities and differences of L2 oral and written development and demonstrate that PT can be applied to L2 writing.

The study aimed to examine the interrelationships between growth mindset, L2 aptitude, L2 grit, and L2 achievement, while also exploring the moderating role of gender in these interactions. A sample of 236 English-major students participated in the study by completing a language aptitude test and a questionnaire. The results of path analyses indicated that both aptitude and L2 grit similarly and positively predicted L2 achievement. The growth mindset had no direct effect on L2 achievement, whereas its indirect effects reached statistical significance. Moreover, growth mindset and L2 grit were found to be unrelated to L2 aptitude. Although female and male students did not differ significantly in their growth mindset, L2 aptitude, L2 grit, and L2 achievement scores, Multi-Group Path Analyses unveiled subtle gender differences.

This cross-sectional and longitudinal study sought to refine the measurement of foreign language learning boredom (FLLB) and examine its links with overall/skill-specific second and foreign language (L2) achievement (curriculum-based course exam scores) and proficiency (Cambridge English test scores). In Substudy 1, we developed and validated an 11-item Foreign Language Learning Boredom Scale–Short Form among secondary and tertiary English as a foreign language (EFL) learners in China (n1 = 2,223, n2 = 504, n3 = 934, n4 = 1,109). The scale showed sound psychometric properties (i.e., construct/criterion/convergent/discriminant/predictive validity, reliability, and measurement invariance across time and groups). In Substudy 2, structural equation modeling results show that FLLB had a consistent modest negative effect on overall and skill-specific (vocabulary and grammar, listening, reading, and writing) L2 achievement and proficiency (n4 = 1,109). Substudy 3 was a 12-month three-semester longitudinal investigation (n4 = 1,109). Cross-lagged panel modeling results show that L2 achievement predicted subsequent FLLB negatively, while FLLB did not predict subsequent L2 achievement.

Multilingualism in the context of academic publishing involves beliefs and actions manifested through publications in multiple languages. However, a systematic analysis of how academic journals practice multilingualism has been scant. Therefore, the present study analyzed how indexed journals of applied linguistics promote and practice multilingualism following their scopes and language policies (LPs). Initially, 67 journals underwent screening based on their “aims and scope,” resulting in 11 journals that actively promoted multilingualism. Employing a critical discourse analysis (CDA) framework, the main analysis focused on the assumptions embedded within the journals’ LPs. The findings indicated an incongruity between the journals’ stated commitment and their practices of multilingualism. Specifically, all the journals mandated submissions exclusively in English with implicit biases toward native speakerism. The study underscores the need for a collective effort within and beyond the applied linguistics community to address linguistic biases and for more equitable and inclusive academic publishing practices.

Manual production enhances learning and recall of signs by hearing second language learners; however, the mechanisms enabling this effect are unclear. We examined whether the motor encoding (somatosensory feedback) that occurs during sign production benefits learning and whether it interacts with sign iconicity, which also enhances learning. American Sign Language (ASL) signs varying in iconicity were learned either via production (repetition) with the eyes closed or via observation without production. Signs learned via production were recalled more accurately than signs learned via observation, indicating that motor encoding from manual production enriches the representations of signs. Moreover, the effect of motor encoding interacted with iconicity, suggesting that motor encoding may particularly enhance the recall of signs low in iconicity. Together, these results reveal the importance of somatosensory feedback as a key mechanism underlying the beneficial effect of production on sign learning, demonstrating that feeling one’s own signing promotes learning and recall of signs.

Elicited imitation (EI) tasks are a practical tool for measuring second language (L2) knowledge and skills. In this study, we implemented a web-based EI task that measures English morphosyntactic knowledge and compared its measurement properties to a traditional laboratory-based EI. A cohort of 149 L2 English learners engaged in the web-based EI task, and 151 participants completed a traditional lab-based EI counterpart. Correlation analyses revealed a significant, comparable relationship between English proficiency and the two EI versions, with the ungrammatical items showing less consistency that neither improved nor harmed the overall EI effectiveness. Factor analyses corroborated the validity of web-programmed EI, with both EI versions relating similarly to time-pressured, implicit knowledge and untimed, explicit knowledge measures. Our results suggest the potential for utilizing web-based EI to substitute lab-based tasks, enabling larger-scale, more diverse sampling. We end with implications for future web-based EI task users and include a coding guideline for customized web-based EI use.

Despite the widespread use and effectiveness of the Modern Language Aptitude Test (MLAT) composite score in predicting individual differences in L2 achievement and proficiency, there has been little examination of MLAT subtests, although they have potential for illuminating components of L2 aptitude and the mechanism of prediction. Here we use regression commonality analysis to decompose the predictive variance from the MLAT into unique components for each subtest alone and for each possible combination of subtests (duos, trios, etc.) that may have shared variance. The results, from a longitudinal study of 307 U.S. secondary students during 2 years of Spanish learning, provide strong evidence for the role of literacy-related skills in all subtests and in predicting all L2 outcomes. These and other results support a view of L1 literacy and language skills leading to metalinguistic development, which in turn leads to stronger L2 aptitude and achievement.