The current study set out to examine to what degree age of acquisition (AOA), defined as a learner’s first intensive exposure to a second language (L2) environment, mediates the final state of postpubertal, spoken vocabulary attainment. In Study 1, spontaneous speech samples were elicited from experienced Japanese users of English (n = 41) using storytelling and interview tasks. The samples were analyzed using a range of corpus- and rater-based lexical measures and compared to the speech of inexperienced Japanese speakers (n = 40) and native speakers of English (n = 10). The results showed that most experienced L2 learners tended to demonstrate nativelike proficiency for relatively easy lexical dimensions of speech (i.e., richness), but that AOA appeared to play a key role in predicting the ultimate attainment of relatively difficult lexical dimensions (i.e., appropriateness). In Study 2, the findings were successfully replicated with experienced L1 Polish users of English (n = 50).

Since Gisela Granena’s influential work, LLAMA D v2, a sound recognition subtest of LLAMA aptitude tests, has been used as a measure of implicit learning aptitude in second language acquisition research. The validity of this test, however, is little known and the results of studies with this instrument have been somewhat inconsistent. In this study, we tested the hypothesis that researchers’ variable test instructions are the source of the inconsistent results. One hundred fourteen English monolinguals were randomly assigned to take LLAMA D v2 under one of three test instruction conditions. They also completed two implicit aptitude tests, three explicit aptitude tests, and a sound discrimination test. The results showed that, regardless of the type of test instructions, LLAMA D scores did not align with implicit aptitude test scores, indicating no clear evidence of the test being implicit. On the contrary, LLAMA D scores were negatively associated with scores on one implicit aptitude test, the Serial Reaction Time (SRT) task, but only in the condition where the instructions drew participants’ focal attention to the stimuli. This negative association was interpreted as focal attention working against learning in the SRT task. Implicit learning aptitude may be the degree to which one is able to process input without focal attention.

Personality has been identified as a possible antecedent to emotions experienced in the foreign language (FL) classroom. However, contrasting results and differing personality models have resulted in ambiguous findings. This study set out to delve deeper into the role of personality as a predictor of FL emotions through a series of increasingly restrictive statistical models on a sample of n = 246 FL learners. The relationships between personality—operationalized as global and lower order factors in the five factor model—and the FL emotions of Foreign Language Enjoyment, Anxiety, and Boredom were examined. The global factors of Neuroticism, Extraversion, and Conscientiousness, and the lower order factors of Trust, Dutifulness, and Cheerfulness were significant predictors of FL emotions. However, the complexity of personality as a predictor variable is demonstrated in the intricacy of the results and as such the inclusion of personality in explanatory models of FL emotions ought to be approached with caution.

The congruency effect—that is, faster and more accurate processing of congruent multiword units, has been demonstrated in multiple studies. It is still unclear, however, what its underlying mechanism is, and how congruency may interact with other factors. Using an acceptability judgement task, this study examined the congruency effect in immersive (Experiment 1) and nonimmersive (Experiment 2) L2 learners’ collocational processing while taking into account L2 collocation frequency, immersive learners’ L2 use, their length and starting age of immersion, nonimmersive learners’ length of instruction, and their L2 proficiency. The study also tested whether L1 counterparts of words in L2 collocations were activated. Nonmmersive learners showed a congruency effect in both processing speed and accuracy. In contrast, immersive learners were affected by congruency only in processing accuracy. Higher L2 collocation frequency, greater length of instruction, and higher L2 proficiency did not reduce the congruency effect, whereas longer duration of immersion improved the processing of incongruent items. An effect of L1 lexical frequency was found, an indication of L1 activation. Results were discussed in light of how L2 proficiency and experiences changed the amount of L1 influence in L2 collocational processing.

Second language (L2) research on input manipulation has focused mainly on increasing the salience of target structures, but presentation formats of L2 input can be another important aspect for manipulation. This study compared the horizontal, vertical, and adjacent formats for presenting the characters, pinyin, and English meaning of L2 Chinese vocabulary, by recruiting 69 English native speakers to study 30 Chinese words in these formats. Learning outcomes were indexed with vocabulary gain scores from pretest to posttest. Learner perceptions of the learning process were recorded with ratings and reasons for preference among these formats. The quantitative results showed the adjacent format generally led to higher gain scores than the other two formats and that L2 proficiency also contributed positively. To learners, the adjacent format was the least preferred, but preference ratings were not associated with gain scores. The qualitative findings suggested format familiarity and layout features as main factors of learner preference.

The present study investigates bilinguals’ capacity to rapidly establish memory traces for novel word forms in a second language (L2), as a function of L2 linguistic proficiency. A group of Chinese-English bilinguals with various English proficiency levels were presented with a reading-aloud task, consisting of 16 pseudowords and 16 English words repeatedly presented across six training exposures. Behavioral and neurophysiological data were collected, and modulations in the word-length effect across repetitions were measured as an index of transition from sublexical to lexical involvement. Results revealed that higher L2 proficiency was associated with decreased word-length effect on novel words, reflected in both naming latencies and early N1 and P200 brain responses. In contrast, lower proficiency learners appeared to engage in effortful letter-to-sound decoding processes, with higher attentional allocation to the letter sequence and greater use of sublexical processing across exposures. Our findings highlight the need to tackle specific grapheme-to-phoneme skills for efficient learning of L2, particularly in populations where the L1 is nonalphabetic.

This study examined how linguistic complexity features contribute to second language (L2) processing effort by analyzing the Dutch English-L2 learners’ eye movements from GECO and MECO, two eye-tracking corpora. Processing effort was operationalized as reading rate, mean fixation duration, regression rate, skipping rate, and mean saccade amplitude. In Study 1, the lexical, syntactic, and discoursal indices in 272 snippets of a novel in GECO were regressed against these eye-movement measures. The results showed that the one-component partial least square regression (PLS-R) models could explain 11%–37% of the variance in these eye-movement measures and outperformed eight readability formulas (six traditional and two recent cognitively inspired formulas based on the readers’ perception on text difficulty) in predicting L2 processing effort. In Study 2, the eye-tracking data from MECO were used to evaluate whether the findings from Study 1 could be applied more broadly. The results revealed that although the predictability of these PLS-R components decreased, they still performed better than the readability formulas. These findings suggest that the linguistic indices identified can be used to predict L2 text processing effort and provide useful implications for developing systems to assess text difficulty for L2 learners.

Research has indicated that lexical richness is an important indicator of second language (L2) proficiency. However, most research has examined written, cross-sectional English L2 corpora and does not necessarily indicate how spoken lexical use develops over time or whether observed trends are stable across L2s. This study adds to previous research on the development of spoken vocabulary by investigating lexical features of L2 Spanish learners over a 21-month period, using the LANGSNAP corpus. Multiple lexical richness indices used in previous studies were examined including lexical diversity, word frequency, word concreteness, and bigram strength of association. Linear mixed-effects models were run to examine changes over time. The results suggest that although some features of lexical richness (e.g., word frequency) see meaningful change over time, others (e.g., bigram T score) may not be indicative of L2 oral development.

The study investigates whether comprehension of derived words in text context requires a complete understanding of word parts. It explores comprehension of derived words as a function of learner proficiency and contextual clues. Ninety English-as-a-foreign-language learners at three proficiency levels participated in three successive tests representing three clues conditions, absence of clues, availability of syntactic clues, and availability of syntactic and semantic clues. They had to supply the meaning of 22 derived pseudowords constructed with nonword stems and 22 frequent affixes—for example, stacement, gummful. The meanings of the nonword stems were provided. Test scores were compared by 3 (proficiency level) × 3 (clue condition) analysis of variance with repeated measures. The results showed effects of both variables, proficiency and clues. The largest increase in comprehension scores occurred with the addition of syntactic clues. The results imply that derived forms of familiar base words can be understood even when learners’ receptive morphological knowledge is not complete.

This study presents a reanalysis of existing data to investigate whether a relationship between perception and production abilities regarding a challenging second-language (L2) phonological contrast is observable (a) when both modalities must rely on accessing stored lexical representations and (b) when there is an asymmetry in task focus between perception and production. In the original studies, German learners of English were tested on their mastery of the English /ɛ/-/æ/ contrast in an auditory lexical decision task with phonological substitutions, a word-reading task, and a segmentally focused imitation task. Results showed that accurate nonword rejection in the lexical decision task was predicted by the Euclidean distance between the two vowels in word reading but not in imitation. These results extend previous findings to lexical perception and production, highlight the influence of task focus on the degree of coupling between the two modalities, and may have important implications for pronunciation training methods.

A slowdown or a speedup in response times across experimental conditions can be taken as evidence of online deployment of knowledge. However, response-time difference measures are rarely evaluated on their reliability, and there is no standard practice to estimate it. In this article, we used three open data sets to explore an approach to reliability that is based on mixed-effects modeling and to examine model criticism as an outlier treatment strategy. The results suggest that the model-based approach can be superior but show no clear advantage of model criticism. We followed up these results with a simulation study to identify the specific conditions in which the model-based approach has the most benefits. Researchers who cannot include a large number of items and have a moderate level of noise in their data may find this approach particularly useful. We concluded by calling for more awareness and research on the psychometric properties of measures in the field.

Meta-analyses play an instrumental role in informing second language (L2) theory and practice. However, current (i.e., classic) approaches to meta-analysis are limited in their ability to do so because they often fail to capture the complexity inherent in primary studies’ research designs. As we argue in this article, when complex L2 studies are represented by simplistic meta-analyses, the latter cannot reach its potential to contribute to the development of cumulative knowledge. To mitigate this issue, we first discuss the fundamental problems of the classic approaches to meta-analysis of complex L2 research. Second, we introduce an alternative meta-analytic framework that will address those problems. Third, we apply the meta-analytic framework discussed to a complex L2 domain. Fourth, we offer free software to facilitate the conduct of the alternative meta-analytic approach described. Finally, we discuss the implications of this alternative framework for making evidence-based recommendations to the relevant stakeholders.

Although lexical diversity is often used as a measure of productive proficiency (e.g., as an aspect of lexical complexity) in SLA studies involving oral tasks, relatively little research has been conducted to support the reliability and/or validity of these indices in spoken contexts. Furthermore, SLA researchers commonly use indices of lexical diversity such as Root TTR (Guiraud’s index) and D (vocd-D and HD-D) that have been preliminarily shown to lack reliability in spoken L2 contexts and/or have been consistently shown to lack reliability in written L2 contexts. In this study, we empirically evaluate lexical diversity indices with respect to two aspects of reliability (text-length independence and across-task stability) and one aspect of validity (relationship with proficiency scores). The results indicated that neither Root TTR nor D is reliable across different text lengths. However, support for the reliability and validity of optimized versions of MATTR and MTLD was found.