This study examines when and how second language (L2) learners begin to exhibit sensitivity to key factors influencing the choice between the English double object and prepositional object constructions. While previous research has shown that such choices in native speakers are influenced by such factors as animacy, pronominality and verb bias, little is known about the developmental timing of these effects in L2 production. Using 5,785 dative constructions from a large-scale learner corpus, we analyzed how these variables interact with learners’ proficiency levels across 23 verbs. We found that learners showed systematic sensitivity to all of these factors, including statistical verb bias derived from a native speaker corpus (Corpus of Contemporary American English), at much earlier stages than previously suggested. These results suggest that learners may possess a cognitive bias that maps preexisting conceptual structures onto linguistic constructions, reflecting more than mere statistical learning.

Dual subtitles, combining captions (audio transcription) with subtitles translated into another language, are increasingly used in language learning. However, how they shape visual attention remains unclear. In the present experiments, we tracked the eye movements of Spanish–English bilinguals, as they viewed instructional videos with either no subtitles (Experiment 1) or dual subtitles (Experiment 2), manipulating subtitle position and audio language. Without subtitles, L1 audio focused gaze on the speaker’s eyes, while L2 audio distributed it between the eyes and mouth. With dual subtitles, gaze shifted strongly to the text, with a preference for the top line, which attracted more viewing time regardless of language. Viewers selectively attended to the line matching the audio. Comprehension improved for L2 audio with subtitles, while L1 comprehension was unaffected. Our findings demonstrate that display layout and language alignment jointly govern attentional allocation in bilingual viewing, with direct implications for L2 instructional design.

Bilinguals vary in their daily-life language use and switching behaviours, which are also frequently studied in relation to other processes (e.g., executive control). Measuring daily-life language use and switching often relies on self-reported questionnaires, but little is known about the validity of these questionnaires. Here, we present two studies examining test–retest reliability and validity of language-use questionnaires (relative to Ecological Momentary Assessment, Study 1) and language-switching questionnaires and tasks (relative to recorded daily-life conversations, small-scale Study 2). Test–retest reliability and validity of the LSBQ (Anderson et al., 2018) were high and moderate, respectively, suggesting this questionnaire can capture daily-life language use well. Although only examined with a small sample size, Study 2 suggested relatively low validity of most language-switching questionnaires, with short language-production tasks potentially offering a more valid assessment. Together, these studies suggest that tools are available to reliably capture language use and switching with (a certain degree of) validity.

Previous research has highlighted that supplementing standard group-level event-related potential analyses with assessments of individual variation can enhance our understanding of language-related brain activity. The present study pursues this approach by examining bilingual speakers’ brain responses to morphologically complex word forms in both their native (German, L1) and their second language (English, L2). We tested 108 bilingual speakers using an ERP violation paradigm examining overapplications of regular verb inflections (‘regularizations’) and of irregular ones (‘irregularizations’). We found a striking L1/L2 contrast within the same bilingual speakers, a left-anterior negativity for regularizations in the L1 and a positivity (P600) for both violation types in the L2. Consistent with previous research, individuals’ brain responses were found to vary along negativity-/positivity-dominant effects. However, the crucial L1/L2 contrast in participants’ brain responses to regularizations was stable across individual differences. We conclude that linguistic constraints, that is, violation type and language status (L1 vs. L2), limit individual variability.

Learning a second language (L2) is challenging partly due to perceptual strategies inherited from learners’ first language. For example, speakers of tone languages like Mandarin over-use pitch in English prosody perception and production. We developed a novel training paradigm to help Mandarin learners adopt more native-like strategies by enhancing their use of duration relative to pitch cues during prosody categorization. After prosody training, participants used duration more during phrase boundary categorization but showed no clear change for contrastive focus and lexical stress, suggesting that cue weighting training is most effective when targeting a feature’s primary cue. The control group, who practiced English vocabulary, relied more on pitch in lexical stress categorization and phrase boundary production after training, suggesting that without targeted instruction, listeners default to existing strategies. Our findings demonstrate that although default strategies in L2 speech perception are difficult to resist, lifelong perceptual habits can be adjusted with training.

This study examined the acoustic realization of focus in Cantonese-English bilingual autistic children’s first language (L1) Cantonese, compared to bilingual typically developing (TD) children and adults, and explored the effects of bilingualism on the production. Results from an elicitation task showed that bilingual autistic children primarily relied on duration to mark focus in L1 Cantonese, similar to adults, but exhibited weaker use of pitch and intensity compared to bilingual TD children. Second language (L2) English exposure and proficiency did not influence focus marking in bilingual autistic children likely due to their later and reduced English exposure compared to TD children. Conversely, bilingual TD children’s prosodic use was modulated by English exposure and proficiency. These findings reveal that bilingualism does not hinder autistic children’s prosodic focus production in their L1 Cantonese and highlight distinct bilingualism effects on prosodic focus production in autistic and TD children.

It has been argued that lexical access in bilinguals is language nonselective. However, little is known about how the input modality (spoken or written) affects cross-language activation during listening and reading. The current study characterizes the nature of within- and cross-language competition for spoken and written words in adults who are bilingual and biliterate in Spanish and English. Using a recently developed cross-modality version of the Visual World Paradigm, we found that competition differs for spoken and written words. For spoken words, the auditory stimulus unfolds overtime giving an additional boost to within- and cross-language competition. Conversely, written words can be seen at once, and thus, incremental processing is less of a factor, resulting in less competition within a language and no competition across languages. The findings show that word recognition is fundamentally language nonselective but can behave in selective ways depending on the modality of the input and language experience.

Word frequency databases like SPALEX and SUBTLEX-ESP treat Spanish as a uniform language, but prior studies and an initial survey (Experiment 1) revealed significant lexical differences between Spanish in Spain and Latin American countries, especially Chile. To establish subjective frequencies of Spanish word usage, an extended survey (Experiment 2) was conducted with Chilean participants, categorizing words by usage area: General, Spain, Chile, and Latin America. Consistent with the initial survey, Chilean participants assigned subjective higher ratings to General and Chilean words. In a lexical decision experiment (Experiment 3), participants responded faster and more accurately to words from these categories. Using survey data, simulations with Multilink+ (Experiment 4) revealed that subjective word ratings better predicted Chilean reaction times than frequencies from existing databases. These findings emphasize the need to address Spanish dialectal differences in research, with word ratings offering a more accurate measure of region-specific lexical nuances than current databases.

This study investigates an asymmetry in (Mandarin) Chinese-English word-internal code-switching: while Chinese inflectional morphemes readily attach to English verbs, Chinese derivational morphemes are consistently rejected when combined with English lexical bases. This pattern raises questions about how the free morpheme constraint should be formulated in bilingual grammar. Building on the phonetic form (PF) interface condition, as proposed in MacSwan’s [Generative approaches to codeswitching. In B. E. Bullock & A. J. Toribio (Eds.), The Cambridge handbook of linguistic code-switching (pp. 309–335). Cambridge University Press (2009)], we argue that the asymmetry is best explained in a lexicalist model that permits post-syntactic affixation. In this approach, inflectional morphology may attach at PF through PF merger, whereas derivational morphology is assembled prior to syntax. The observed asymmetry thus follows from the distribution of morphology across components and the conditions governing the mapping from syntax to phonology. The findings show that derivational timing shapes code-switching, support the viability of lexicalist models that permit post-syntactic affixation, and indicate that word-internal code-switching is permitted under specific interface conditions.

Previous studies suggest that bilinguals can quickly identify the language to which a word belongs in order to suppress a task-irrelevant language. The current study tested whether nontarget language suppression occurs at the lexical and/or semantic levels and whether the degree of processing differs across these representational levels. Spanish–Basque bilinguals classified words by language membership and animacy, and event-related potential (ERP) results demonstrated that task demands to attend to a single target language reduced frequency effects and eliminated concreteness effects for words in the nontarget language. Results support a partially selective mechanism of bilingual language control based on task demands such that words belonging to the nontarget language are only partially processed at the lexical level and are not processed at a deeper semantic level. These findings specify the locus of bilingual language control in comprehension and call for revisions to models of bilingual visual word recognition such as BIA+.

This study examines sentence comprehension in two in-situ heritage Slovene communities in Italy’s border-shift context, comparing the Gorizia/Trieste (N = 66) and Natisone Valley (N = 43) adult populations with monolingual Slovene speakers. While both heritage groups operate in Italian-dominant bilingual environments near the Slovenian border, they differ in Slovene exposure due to varying institutional support. Using a sentence–picture verification task, this study examines comprehension of non-canonical word order, relative clauses and cataphoric dependencies. The Gorizia/Trieste group performed comparably to monolinguals, demonstrating strong sensitivity to case morphology and syntactic processing. Conversely, the Natisone group showed reduced accuracy and longer response times across all domains, reflecting case system vulnerability and processing limitations linked to reduced exposure. These findings highlight the important role of active maintenance and institutional support, independent of geographical proximity to the mainland, in shaping heritage language grammars and their use.

Proactive language control is thought to regulate the interference from the nontarget language in bilingual contexts in a sustained way. This study examined the persistence of proactive control in cued picture naming. Participants first named pictures in L1 (German) and L2 (English) in pure blocks, then in mixed language blocks and finally again in pure blocks. In mixed blocks, there were language switch costs, and L1 responses were generally slower than L2 responses (“L1 slowing”). Critically, L1 remained slower than L2 even in postmixing single-language blocks. This persisting L1 slowing suggests overshooting control that downregulates lexical access to L1 representations in a sustained manner. Yet, this persistence of L1 slowing was found only in the first single-language block after the mixed language blocks and no longer in the second postmixing block, suggesting that proactive control has inertia but dissipates over time.

Simultaneous interpreting (SI), a challenging task enabled by bilingualism, is claimed to distinctly tax working memory (WM). However, causal designs are missing, limiting our understanding of the phenomenon. We recruited 50 Chinese-English bilinguals and assessed their WM performance (alongside inhibitory and fluency outcomes) before and after L1–L2 SI or a control task (text comprehension). WM scores (especially under high-demand, multimodal conditions) increased after text comprehension but not after SI, adjusting for age of L2 appropriation, years of L2 use, L2 proficiency and SI competence. Of note, WM was assessed immediately before and after SI, ruling out other cognitive influences. Conversely, no distinct patterns were observed on inhibitory or fluency tasks. Briefly, this activity seems to hinder practice-related WM gains – a finding that expands contemporary accounts of interpreting.

Bilingualism research has long been challenged by a lack of a unified approach to quantifying language dominance and degree of multilingualism. While numerous questionnaires (e.g., LHQ, BLP, LEAP‑Q, and LUQ) provide valuable data on language background variables, they lack a standardized formula to compute key measures from it. We introduce two formulas that synthesize critical linguistic variables to efficiently calculate language dominance and a multilingualism score that ranges from perfect monolingualism to native-like proficiency in multiple languages. Validation across two large datasets shows our dominance measure closely aligns with more complex PCA methods while being simpler and more efficient.

We examined the growth of English-L2 clausal density (CD) in narrative language samples from 129 school-age Syrian refugee children during their first 5 years of residency in Canada. First, we found that CD showed unique developmental trajectories from MLUw, and relatively rapid acquisition, consistent with studies with non-refugee participants. Second, faster growth in CD was associated with superior cognitive abilities and higher maternal education. An older-age advantage was found at Time 1, but a younger-age advantage emerged across Time 2–3. Factors more specific to the refugee experience (time in refugee camps and wellbeing difficulties) also predicted variance in CD and MLUw development but to a lesser extent. Finally, modeling performance on sentence repetition tasks revealed stronger contributions of lexical diversity and MLUw than CD. We conclude that complex syntax is relatively resilient in the L2 acquisition of refugee children and that CD in naturalistic production and SRT capture different abilities.

Bilingual experience may enhance attentional control, but little work has addressed whether monolinguals and bilinguals differ in allocating attentional resources. Focusing on speech processing, we examined listening effort via pupillometry in English monolinguals and simultaneous bilinguals, while they listened to passages in a familiar or unfamiliar language. Results demonstrated similar pupil responses across conditions in bilinguals, yet monolinguals showed significantly larger pupil size when listening to the unfamiliar language than the familiar one. Further, more English exposure (especially a longer stay in an English-speaking family) correlated with smaller pupil size in the familiar language condition. Overall, our findings suggest that bilinguals tend to exhibit greater listening effort than monolinguals, and a more cognitively demanding situation (i.e., listening to an unknown language) requires more effort in monolinguals. With this, we broadened the scope of research on bilingual cognition and demonstrated that bilingualism affects attentional resource allocation in spoken language processing.

Research on multilingualism often assumes homogeneity within monolingual and multilingual groups, overlooking diversity in language environments, such as differences in language exposure and combinations. This study examines three such diversity indicators – language entropy, context entropy and linguistic distance – and their relationship to vocabulary in 4- to 5-year-old mono- and multilingual children (N = 257). Results reveal significantly greater vocabulary in monolinguals than multilinguals when comparing one language, but multilinguals outperform monolinguals on conceptual vocabulary. Vocabulary size in multilinguals showed a quadratic relationship with language and context entropy, initially increasing but declining at higher entropy levels. Additionally, children with greater linguistic distances generally had larger dominant vocabularies. However, within the group with high linguistic distance, further increased distance was linked to smaller dominant vocabularies. These findings suggest that the applied diversity indicators capture meaningful variation in language environments, offering valuable insights about diversity in environments on vocabulary outcomes in multilingual children.

This study investigated whether differences in executive control exist between bilinguals and monolinguals who share a dual-language context. We compared functional monolingual and bilingual groups’ cognitive performance and the correlation between self-reported and objective linguistic variables and cognitive outcomes. Group comparisons revealed no significant differences between functional monolinguals and bilinguals on inhibition, task switching and updating of information. However, distinct correlational patterns were observed within groups. In functional monolinguals, participants with lower bilingualism scores showed better task-specific inhibition (Color–Word part of the Stroop task) and a better ability to monitor for conflicts (Digits Forward task). In contrast, bilinguals with higher degrees of bilingualism showed better overall inhibition outcomes (Stroop effect). Findings are discussed in terms of the importance of adopting more comprehensive methodological approaches to study bilingualism as a heterogeneous phenomenon, considering the diversity within each group and the cultural and linguistic context in which the bilingual experience takes place.

The present study examines how L1-English learners acquire Korean subject honorification – a system that is socio-pragmatic in interpretation but syntactically constrained. Using a multi-method design (corpus analysis, politeness ratings, and self-paced reading), we find that learners show increasing sensitivity to politeness norms yet limited awareness of morphosyntactic constraints. In corpus analysis, learners used subject honorification almost exclusively alongside addressee honorification, indicating limited functional differentiation. In politeness ratings, learners consistently associated the subject honorific suffix with greater politeness, regardless of subject type, diverging from native speakers’ judgments. In self-paced reading, learners were sensitive to semantic anomalies (e.g., inanimate subjects) but not to morphosyntactic violations. Together, these findings suggest that learners interpret the subject honorific suffix as a general politeness marker, likely due to its low cue validity and frequent co-occurrence with pragmatically salient features. Our results highlight how cue reliability and competition shape L2 acquisition pathways under conditions of noisy linguistic representations.

Continuous immersion in a second language causes speakers’ first language to change, a phenomenon known as L1 attrition. We explored (1) whether bilingual native Mandarin speakers display attrition-related changes in their use of referring expressions in Mandarin after exposure to English and (2) whether the severity of attrition is affected by the amount of exposure to both Mandarin (L1) and English (L2) and English proficiency. All participants completed a questionnaire to assess their language experience and a picture description task in spoken Mandarin. The results show that where more monolingual Mandarin speakers preferred null pronouns, bilingual speakers tended to use overt pronouns, suggesting attrition-related changes in their native language which favoured explicitness. Our study also shows that decreased use of L1 coupled with increased use of L2 and higher L2 proficiency are likely to result in a greater degree of attrition, although such an association is statistically unreliable in some models.