The impact of text length on the estimation of lexical diversity has captured the attention of the scientific community for more than a century. Numerous indices have been proposed, and many studies have been conducted to evaluate them, but the problem remains. This methodological review provides a critical analysis not only of the most commonly…

A central question in multilingualism research is how multiple languages interact. Most studies have focused on first (L1) and second language (L2) effects on a third language (L3), but a small number of studies dedicated to the opposite transfer direction have suggested stronger L3 influence on L2 than on L1 in postpuberty learners. In our study,…

This study longitudinally examined the effects of cognitive and sociopsychological individual differences (aptitude, motivation, personality) and the quantity and quality of second language (L2) experience on L2 speech gains in naturalistic settings. We elicited L2 spontaneous speech from 50 Chinese learners of English at the beginning and the end…

This study investigated how much practice is necessary for learners to attain durable second language (L2) grammar knowledge. Using digital flashcards, 119 participants practiced translating 12 sentences into an artificial language, followed by feedback, until they had typed all sentences correctly. Participants repeated this activity in one, two,…

This study examined structural priming during online second language (L2) comprehension. In two self-paced reading experiments, 64 intermediate to advanced Chinese learners of English as a foreign language read coordinated noun phrases where the conjuncts had either the same structure or different structures. Experiment 1 showed that the second…

Second language (L2) speakers often experience difficulties in learning words with L2-specific phonemes due to the unfaithful lexical encoding predicted by the fuzzy lexical representations hypothesis. Currently, there is limited understanding of how allophonic variation in the first language (L1) influences L2 phonological and lexical encoding.…

Second language acquisition (SLA) research offers valuable insight on how languages are learned and how they coexist and influence each other. Sign language learners offer unique perspectives on SLA, allowing researchers to test theories that are otherwise constrained by access to only one modality. Current literature on sign language learning…

Second language implicit learning research has shown that a variety of linguistic features can be acquired without awareness. However, this research overwhelmingly uses comprehension tests to measure implicit learning. It remains unclear whether newly acquired implicit knowledge can also be recruited for production. To address this question, we…

In this study, we examined the effect of previewing unfamiliar vocabulary on the real-time reading behavior of first language (L1) and second language (L2) readers. University students with English as their L1 or L2 read passages with embedded pseudowords. In a within-participant manipulation, definitions of the pseudowords were either previewed…

This study investigated how students' self-reported individual differences predicted second language (L2) spoken discussion task output, an objective behavioral outcome, in the Japanese university English as a Foreign Language (EFL) context. Although numerous psychological theories are used as a rationale for task-based language teaching (TBLT),…

This study examined the relationship of linguistic complexity, captured using a set of lexical richness, syntactic complexity, and discoursal complexity indices, to second language (L2) learners' perception of text difficulty, captured using L2 raters' comparative judgment on text comprehensibility and reading speed. Testing materials were 180…

Making adults learn from larger linguistic units can facilitate learning article-noun agreement. Here we ask whether initial exposure to larger units improves learning by increasing the predictive associations between the article and noun. Using an artificial language learning paradigm, we taught 106 Hebrew-speaking participants novel article-noun…

This study explores the effects of receptive derivational affix knowledge, derivative frequency, part of speech, and vocabulary breadth on production of derivatives. Twenty-one speakers of English as a first language and 107 learners of English as a second language were asked to produce derivatives for 90 prompt words on a decontextualized…

In this paper, we report a longitudinal study of the effects of procedural task repetition on learners' task performance (i.e., syntactic complexity in relation to lexical complexity). We investigated how task repetition results in differences at the group and individual level across each task interval (T = 7). Intermediate-level Saudi learners of…

The last two decades have seen a significant amount of interest in bilingual language learning and processing. A number of computational models have also been developed to account for bilingualism, with varying degrees of success. In this article, we first briefly introduce the significance of computational approaches to bilingual language…