There has been a substantial amount of research on heritage language acquisition and diachronic change. Although recent work has increasingly pointed to parallels between those two areas, it remains unclear how systematic these are. In this paper, we provide a bird's eye view, illustrating how patterns of diachronic change are mirrored in heritage language grammars. In doing so, we focus on one of the best-described grammaticalization processes – namely, the formation of articles from demonstratives and numerals, reviewing studies on heritage varieties which mirror those processes. Based on this review, we make two main points: that change in heritage language can be predicted based on established diachronic scenarios, and that heritage languages often amplify incipient changes in the baseline. After discussing a number of attested changes in a bilingual context, we identify directions for future research in the domain of determiners in heritage languages.

Much research has been dedicated to the effects of bilingualism on executive control (EC). For bilinguals with aphasia, the interplay with EC is complex. In this systematic review, we synthesize research on this topic and provide an overview of the current state of the field. First, we examine the evidence for EC deficits in bilingual persons with aphasia (bPWA). We then discuss the domain generality of bilingual language control impairments. Finally, we evaluate the bilingual advantage hypothesis in bPWA. We conclude that (1) EC impairments in bPWA are frequently observed, (2) experimental results on the relationship between linguistic and domain-general control are mixed, (3) bPWA with language control problems in everyday communication have domain-general EC problems, and (4) there are indications for EC advantages in bPWA. We end with directions for experimental work that could provide better insight into the intricate relationship between EC and bilingual aphasia.

Questionnaires documenting children's bilingual experience have been used frequently in research on language and cognitive development. However, there has been little investigation of the comparability between these tools. In this review, we (i) provide a list of available questionnaires used to quantify bilingual experience in children; (ii) identify the components of bilingual experience documented across questionnaires; and (iii) discuss the comparability of the measures used to operationalise these components. In doing so, we review 48 questionnaires and identify 32 overarching constructs, manifested as 194 components, and we calculate the frequency with which they are documented. Finally, by focusing on a subset of overarching constructs (language exposure and use, activities, and current language skills), we observe high variability in how they are operationalised across tools. These findings highlight the need for greater transparency in how we document bilingualism and for more comparable measures.

Simultaneous bilingual children sometimes display crosslinguistic influence (CLI), widely attested in the domain of morphosyntax. It remains less clear whether CLI affects bilinguals’ event construal, what motivates its occurrence and directionality, and how developmentally persistent it is. The present study tested predictions generated by the structural overlap hypothesis and the co-activation account in the motion event domain. 96 English–French bilingual children of two age groups and 96 age-matched monolingual English and French controls were asked to describe animated videos displaying voluntary motion events. Semantic encoding in main verbs showed bidirectional CLI. Unidirectional CLI affected French path encoding in the verbal periphery and was predicted by the presence of boundary-crossing, despite the absence of structural overlap. Furthermore, CLI increased developmentally in the French data. It is argued that these findings reflect highly dynamic co-activation patterns sensitive to the requirements of the task and to language-specific challenges in the online production process.

Language mixing is common in bilingual children's learning environments. Here, we investigated effects of language mixing on children's learning of new words. We tested two groups of 3-year-old bilinguals: French–English (Experiment 1) and Spanish–English (Experiment 2). Children were taught two novel words, one in single-language sentences (“Look! Do you see the dog on the teelo?”) and one in mixed-language sentences with a mid-sentence language switch (“Look! Do you see the chien/perro on the walem?”). During the learning phase, children correctly identified novel targets when hearing both single-language and mixed-language sentences. However, at test, French–English bilinguals did not successfully recognize the word encountered in mixed-language sentences. Spanish–English bilinguals failed to recognize either word, which underscores the importance of examining multiple bilingual populations. This research suggests that language mixing may sometimes hinder children's encoding of novel words that occur downstream, but leaves open several possible underlying mechanisms.

Reports suggest that the development of a child's understanding of the mind (ToM) is enhanced in bilingual children. This is usually ascribed to different features of executive functioning (EF), though there is not a lot of empirical support for that position. Instead, published studies suggest an association between linguistic processes such as sociolinguistic sensitivity, metalinguistic awareness, language proficiency, and bilinguals’ ToM development. Coupled with evidence that bilinguals rely more on person-intention cues and show enhanced abilities to repair breakdowns in communication compared to monolinguals, this paper presents the argument that navigating sociolinguistic environments with agents differing in linguistic knowledge helps bilingual children develop an enhanced ToM. Additionally, this review includes relevant literature on deaf children and cultural variations and ToM, which are indicative of other situations in which contextual variants, especially those that are linguistically mediated, have an impact on the development of ToM that is independent of EF.

Despite its prominent use among bilinguals, psycholinguistic studies reported code-switch processing costs (e.g., Meuter & Allport, 1999). This paradox may partly be due to the focus on the code-switch itself instead of its potential subsequent benefits. Motivated by corpus studies on CS patterns and sociopragmatic functions of CS, we asked whether bilinguals use code-switches as a cue to the lexical characteristics of upcoming speech. We report a visual world study testing whether code-switching facilitates the anticipation of lower-frequency words. Results confirm that US Spanish–English bilinguals (n = 30) use minority (Spanish) to majority (English) language code-switches in real-time language processing as a cue that a less frequent word would ensue, as indexed by increased looks at images representing lower- vs. higher-frequency words in the code-switched condition, prior to the target word onset. These results highlight the need to further integrate sociolinguistic and corpus observations into the experimental study of code-switching.

Cognates – words that share form and meaning between languages – are processed faster than control words. However, is this facilitation effect merely lexical in nature or does it cascade to phonological/orthographic (i.e., sub-lexical) processes? This study compared cognate effects in spoken and typewritten production, which share lexical, but not sub-lexical processes. Dutch–English bilinguals produced English names for pictures representing Dutch–English cognates and control words in either the spoken or typewritten modality. Onset latencies were shorter and accuracy was higher for cognates vs. control words and this effect was similar in both modalities. Compared to controls, total latencies in the written modality were similar for cognates with much cross-linguistic overlap, but longer for ones with less overlap. Additionally, error analysis showed that cognates were more affected by L1 interference than controls. These results suggest two different cognate effects: one at the lexical and one at the sub-lexical level.

Orthography plays a crucial role in L2 learning, which generally relies on both oral and written input. We examine whether incongruencies between L1 and L2 grapheme-phoneme correspondences influence bilingual speech perception and production, even when both languages have been acquired in early childhood before reading acquisition. Spanish–Basque and Basque–Spanish early bilinguals performed an auditory lexical decision task including Basque pseudowords created by replacing Basque /s̻/ with Spanish /θ/. These distinct phonemes take the same orthographic form, <z>. Participants also completed reading-aloud tasks in Basque and Spanish to test whether speech sounds with the same orthographic form were produced similarly in the two languages. Results for both groups showed orthography had strong effects on speech perception but no effects on speech production. Taken together, these findings suggest that orthography plays a crucial role in the speech system of early bilinguals but does not automatically lead to non-native production.

Research in second language (L2) learning often considers one modality only during task completion. It is unclear if L2 performance is as accurate whatever the modality. L2 learning at school is characterized by a predominance of written materials. One might expect written L2 word recognition to be more accurate than spoken one. This modality effect could also depend on L2 proficiency and the presence of cognate items, closer orthographically than phonologically for most language pairs. Two experiments were conducted with 50 intermediate proficiency French–English bilinguals. Experiment 1 highlighted this modality effect on accuracy and a session effect reflecting a benefit from oral to written modality on latency. In Experiment 2, which included both cognate and non-cognate words, modality effect was even stronger for cognate words and cognate effect depended on modality. In both experiments, these effects depend on L2 proficiency. These findings are discussed according to bilingual word recognition models.

The present electroencephalographical multi-speaker MMN oddball experiment was designed to study the phonological processing of German native and non-native speech sounds. Precisely, we focused on the perception of German /ɪ-iː/, /ɛ-ɛː/, /a-aː/ and the fricatives [ʃ] and [ç] in German natives (GG) and French learners of German (FG). As expected, our results showed that GG were able to discriminate all the critical vowel contrasts. In contrast, FG, despite their high L2 proficiency level, were only marginally sensitive to vowel length variations. Finally, neither GG nor FG discriminated the opposition between [ʃ] and [ç], as revealed by the absence of MMN response. This latter finding was interpreted in terms of low perceptual salience. Taken together, the present findings lend partial support to the Perceptual Assimilation Model for late bilinguals (PAM-L2) for speech perception of non-native phonological contrasts.

Inspired by information theoretic analyses of L1 speech and language, this study proposes that L1 and L2 speech exhibit distinct information encoding and transmission profiles in the temporal domain. Both the number and average duration of acoustic syllables (i.e., intensity peaks in the temporal envelope) were automatically measured from L1 and L2 recordings of standard texts in English, French, and Spanish. Across languages, L2 acoustic syllables were greater in number (more acoustic syllables/text) and longer in duration (fewer acoustic syllables/second). While substantial syllable reduction (fewer acoustic than orthographic syllables) was evident in both L1 and L2 speech, L2 speech generally exhibited less syllable reduction, resulting in low information density (more syllables with less information/syllable). Low L2 information density compounded low L2 speech rate yielding very low L2 information transmission rate (i.e., less information/second). Overall, this cross-language comparison establishes low information transmission rate as a language-general, distinguishing feature of L2 speech.

This study investigated how natural language use influences inhibition in language-unbalanced bilinguals. We experimentally induced natural patterns of language use (as proposed by the Adaptive Control Hypothesis) and assessed their cognitive after-effects in a group of 32 Polish–English bilinguals. Each participant took part in a series of three language games involving real conversation. Each game was followed by two inhibition tasks (stop-signal task and Stroop task). The manipulation of language use in the form of language games did not affect the behavioural measures, but it did affect ERPs. Performance of the inhibition tasks was accompanied by a reduction of P3 and the N450 amplitude differences after games involving the use of L2. The ERP modulations suggest that for bilinguals living in an L1 context the use of L2 enhances neural mechanisms related to inhibition. The study provides the first evidence for a direct influence of natural language use on inhibition.