Previous research has shown that heritage speakers struggle with inflectional morphology. ‘Limitations of online resources’ for processing a non-dominant language has been claimed as one possible reason for these difficulties. To date, however, there is very little experimental evidence on real-time language processing in heritage speakers. Here we report results from a masked priming experiment with 97 bilingual (Turkish/German) heritage speakers and a control group of 40 non-heritage speakers of Turkish examining regular and irregular forms of the Turkish aorist. We found that, for the regular aorist, heritage speakers use the same morphological decomposition mechanism (‘affix stripping’) as control speakers, whereas for processing irregularly inflected forms they exhibited more variability (i.e., less homogeneous performance) than the control group. Heritage speakers also demonstrated semantic priming effects. At a more general level, these results indicate that heritage speakers draw on multiple sources of information for recognizing morphologically complex words.

Languages differ in the preferences for the interpretation of the scope relation between negation and a quantifier. This study investigates the understudied issue of how interpretive preferences associated with a quantifier scope in learners’ L1 and L2 affect their scope interpretations in L3 acquisition. Based on the current models of L3 acquisition, we tested which language, L1 or L2, exerts a stronger effect on the L3 acquisition of quantifier scope. To this end, the study involved two groups of multilingual children (11–13 years old) with different L1s (Chinese or Russian) but with the same L2 (Korean) and L3 (English). The participants completed truth-value judgment tasks designed to investigate their interpretation patterns for English sentences with negation and a quantifier (e.g., Tom did not cut all the trees). The results showed that both groups preferred the L3 interpretation similar to that preferred in their L2, but not in their L1, suggesting a potential L2 influence on L3 acquisition. The study evaluates L3 acquisition theories in light of these results.

In this study we investigated 107 young learners’ L2 English receptive vocabulary knowledge and speaking skills at two points in time, before and after the onset of instruction. We also investigated the role of several individual difference variables: out-of-school exposure to English, length of instruction, analytic reasoning ability, working memory, L1 vocabulary knowledge and prior L2 knowledge. Results show that L2 English proficiency in receptive vocabulary knowledge and speaking skills greatly improved over time and that the effects of schooling and contextual learning are largely additive. The main predictor of the children's proficiency at time 2 was their L2 prior knowledge, which they had acquired through contextual language learning before getting formal education. When considering the other variables that predicted L2 proficiency, the contribution of internal variables (L1 vocabulary size and working memory) was considerably smaller than that of external variables (out-of-school exposure and length of instruction).

While heritage language phonology has attracted a great deal of attention, little is known about the development of heritage phonological grammars. This study examines the production of the Spanish trill /r/ by school-aged (9-10 years) and adult heritage speakers. Results showed that the adult heritage speakers produced the trill in a more target-like manner than the child heritage speakers, although half of them diverged from non-heritage native baselines reported in other studies. Further analysis of the distribution of trill variants suggests that heritage Spanish trill development occurs in the order of single lingual constriction → frication → multiple lingual constrictions. However, instead of abandoning variants of early stages, some adult heritage speakers kept them in their trill inventories, demonstrating increased variability. Our findings indicate that 9- to 10-year-old heritage speakers are still in the process of developing heritage phonological grammars and even during adulthood their grammars may not reach stability.

Speech perception involves both conceptual cues and perceptual cues. These, individually, have been shown to guide bilinguals’ speech perception; but their potential interaction has been ignored. Explicitly, bilinguals have been given perceptual cues that could be predicted by the conceptual cues. Therefore, to target the perceptual-conceptual interaction, we created a restricted range of perceptual cues that either matched, or mismatched, bilinguals’ conceptual predictions based on the language context. Specifically, we designed an active speech perception task that concurrently collected electrophysiological data from Spanish–English bilinguals and English monolinguals to address the extent to which this cue interaction uniquely affects bilinguals’ speech sound perception and allocation of attentional resources. Bilinguals’ larger MMN-N2b in the mismatched context aligns with the Predictive Coding Hypothesis to suggest that bilinguals use their diverse perceptual routines to best allocate cognitive resources to perceive speech.

This study investigated the contribution of second-language (L2) phonetic categorization abilities and vocabulary size to the phonolexical encoding of challenging non-native phonological contrasts into the L2 lexicon. Two groups of German learners of English differing in L2 proficiency (advanced vs. intermediate) participated in an English lexical decision task including words and nonwords with /ɛ/ and /æ/ (/æ/ does not exist in German), an /ɛ/-/æ/ phonetic categorization task and an English vocabulary test. Results showed that the effects of phonetic categorization and vocabulary size on lexical decision performance were modulated by proficiency: categorization predicted /ɛ/-/æ/ nonword rejection accuracy for intermediate learners, whereas vocabulary did so for advanced learners. This suggests that sufficient phonetic identification ability is key for an accurate phonological representation of difficult L2 phones, but, for learners for whom robust phonetic identification is already in place, their ultimate success is tightly linked to their vocabulary size in the L2.

High-Variability Phonetic Training (HVPT) has been shown to be effective in improving the perception of the hardest non-native sounds. However, it remains unclear whether such training can enhance phonological processing at the lexical level. The present study tested whether HVPT also improves word recognition. Late French learners of English completed eight online sessions of HVPT on the perception of English word-initial /h/. This sound does not exist in French and has been shown to cause difficulty both at the prelexical (Mah, Goad & Steinhauer, 2016) and the lexical level of processing (Melnik & Peperkamp, 2019). In pretest and posttest participants were administered a prelexical identification task and a lexical decision task. Results demonstrate that after training the learners’ accuracy improved in both tasks. Moreover, these improvements were retained four months after posttest. This is the first evidence that short training can enhance not only prelexical perception, but also word recognition.

The masked translation priming effect was examined in Chinese–English bilinguals using lexical decision and semantic categorization tasks in an effort to understand why the two tasks seem to produce different patterns of results. A machine-learning approach was used to assess the participant-based factors that contribute to the sizes of translation priming effects in these tasks. As expected, the participant-based factors that predicted translation priming effects did vary across tasks. Priming effects in lexical decision were associated with higher self-rated listening, reading, and writing abilities in English. Priming effects in semantic categorization were associated with more frequent use of English in daily life, spoken English proficiency, and self-rated listening proficiency in English. These results are discussed within the framework of Multilink, the logic of which is then expanded in an attempt to account for these task differences.

This study investigated how bilingual experience alters neural mechanisms supporting novel word learning. We hypothesised that novel words elicit increased semantic activation in the larger bilingual lexicon, potentially stimulating stronger memory integration than in monolinguals. English monolinguals and Spanish–English bilinguals were trained on two sets of written Swahili–English word pairs, one set on each of two consecutive days, and performed a recognition task in the MRI-scanner. Lexical integration was measured through visual primed lexical decision. Surprisingly, no group difference emerged in explicit word memory, and priming occurred only in the monolingual group. This difference in lexical integration may indicate an increased need for slow neocortical interleaving of old and new information in the denser bilingual lexicon. The fMRI data were consistent with increased use of cognitive control networks in monolinguals and of articulatory motor processes in bilinguals, providing further evidence for experience-induced neural changes: monolinguals and bilinguals reached largely comparable behavioural performance levels in novel word learning, but did so by recruiting partially overlapping but non-identical neural systems to acquire novel words.

Numerous studies have investigated the neural correlates of reading in two languages. However, reliable conclusions have not been established as to the relationship of the neural correlates underlying reading in the first (L1) and second (L2) language. Here, we conduct meta-analyses to address this issue. We found that compared to L1, the left inferior parietal lobule showed greater activation during L2 processing across all bilingual studies. We then divided the literature into two categories: bilingual participants who learned two languages with different writing systems and bilinguals who learned two languages with similar writing systems. We found that language differences in the neural correlates of reading were generally modulated by writing system similarity, except the region of the left inferior parietal lobule, which showed preferences for L2 reading in both types of bilinguals. These findings provide new insights into the brain mechanisms underlying reading in bilinguals.

To become fluent in a second language, learners need to acquire a large vocabulary. However, the cognitive and affective mechanisms that support word learning, particularly among second language learners, are only beginning to be understood. Prior research has focused on intentional learning and small artificial lexicons. In the current study investigating the sources of individual variability in word learning and their underlying mechanisms, participants intentionally and incidentally learned a large vocabulary of Welsh words (i.e., emulating word learning in the wild) and completed a large battery of cognitive and affective measures. The results showed that, for both learning conditions, native language knowledge, auditory/phonological abilities and orthographic sensitivity all made unique contributions to word learning. Importantly, short-term/working memory played a significantly larger role in intentional learning. We discuss these results in the context of the mechanisms that support both native and non-native language learning.

Bilingualism as it occurs in current societies is a complex, multidimensional and dynamic phenomenon, calling for new approaches to capture this concept. This study shows the feasibility of a person-centred approach by combining measures of the use of and proficiency in the first and second language from 110 young Turkish–Dutch children at two measurement waves, using two existing datasets. Latent Profile Analysis revealed four profiles, equivalent at age four and six: 1) Dominant L1 use, relatively low L1 and L2 proficiency, 2) Dual L1 and L2 use, around average L1 and L2 proficiency, 3) Dominant L1 use, relatively high L1 and L2 proficiency and 4) Dominant L2 use, relatively high L2 proficiency. Latent Transition Analysis indicated that children changed in profiles over time. Regression analyses showed that profiles were differently related to the family's socioeconomic status and children's nonverbal intelligence at age four. No relations were found at age six.

The assumption that everyday language switching trains bilinguals’ executive functions (EF) presupposes that language switching engages domain-general EF. This study examined associations between three types of tasks in a group of Finnish-English late bilinguals: everyday language switching frequency assessed with Ecological Momentary Assessment, language switching performance on a cued bilingual naming task, and EF as measured with Simon, Flanker, and Number-letter tasks. Cued switching performance showed mainly positive associations with EF performance, but the associations between everyday language switching and cued switching performance, and between everyday switching and the EF tasks were largely against our hypotheses. The findings indicate that participants with lower monitoring capacity make more everyday language switches. This speaks against the idea that everyday language switching would facilitate executive functioning. The results suggest that associations between language switching and general EF are more complex than current models assume.