Most existing studies on the relationship between code-switching and executive functions have focused on experimentally induced language-switching, which differs fundamentally from naturalistic code-switching. This study investigated whether and how bilinguals’ code-switching practices modulate different aspects of executive functioning. Our findings suggest that existing processing models of code-switching should be extended by a dual control mode perspective, differentiating between reactive and proactive monitoring. Bilinguals engaging in code-switching types that keep languages more separate (Alternation) displayed inhibitory advantages in a flanker task inducing reactive control. Dense code-switching, which requires bilinguals to constantly monitor cross-linguistic competition, explained performance in proactive monitoring conditions. Furthermore, a correlation between Dense code-switching and response inhibition suggests that linguistic co-activation may persist during articulatory stages of language processing. Crucially, bilinguals outperformed monolinguals at those aspects of the executive system that were trained by their most frequent code-switching habits. This underlines the importance of sociolinguistic variables in bilingualism research.

Language switching experience is assumed to have an effect on domain-general control abilities in bilinguals, but previous studies on the relationship between these two variables have generated mixed results. The present study investigated the effects of bilingual experiences on the interaction between language switching and domain-general control. Thirty-two Dutch–French bilingual young adults executed a bilingual categorisation task to assess their language switching abilities and a Simon task to assess domain-general control. The results show that global response times on the Simon task were correlated to the forward switch cost (from L1 to L2); moreover, interestingly, the forward switch cost was found to be related to recent language exposure but not to the age of second language acquisition. We suggest a monitoring account of language switching to integrate the first finding with previous studies and we interpret the second finding as support for the adaptive control hypothesis.

Mutual Exclusivity (ME) is a prominent constraint in language acquisition, which guides children to establish one-to-one mappings between words and referents. But how does unfolding experience of multiple-to-one word-meaning mappings in bilingual children's environment affect their understanding of when to use ME and when to accept lexical overlap? Three-to-five-year-old monolingual and simultaneous bilingual children completed two pragmatically distinct tasks, where successful word learning relied on either the default use of ME or the ability to accept overlapping labels. All children could flexibly use ME by following the social-pragmatic directions available in each task. However, linguistic experience shaped the development of ME use, whereby older monolinguals showed a greater reliance on the one-to-one mapping assumption, but older bilinguals showed a greater ability to accept lexical overlap. We suggest that flexible use of ME is thus shaped by pragmatic information present in each communicative interaction and children's individual linguistic experience.

Is bilingualism better than monolingualism? Previous work shows that bilinguals have an advantage over monolinguals in cognitive flexibility, the ability to shift between different mental sets. In this study, we explore if bilingualism also provides an advantage in social flexibility, which we define as the ability to (a) switch with ease and adapt between different social environments and (b) accurately read social cues in the environment. Data was collected from 465 monolinguals and 206 bilinguals. Bilinguals reported higher social flexibility than monolinguals. Mediation analyses demonstrated that bilinguals’ social flexibility gave them an advantage over monolinguals in the self-reported frequency of social interactions. This study reports the first evidence of a social flexibility advantage of bilinguals, and it suggests that as bilinguals alternate between two languages, they might also alternate between two cultural worlds, providing tools to adapt to different social environments and facilitating the frequency of social interactions.

Previous studies have shown effects of bilingualism on inhibitory control in preschool children. However, these effects only held for ‘conflict tasks’, and not delay of gratification tasks, and other domains of executive functioning were not investigated. For older children, previous studies have found relationships between bilinguals’ advantages and home language environment. This study investigates effects of bilingualism and bilingual home language environment on executive functioning in three-year-old children. 200 bilingual and 829 monolingual three-year-olds performed tasks of inhibitory control, working memory, and selective attention. Home language environment characteristics were assessed through a parental questionnaire. The bilinguals outperformed the monolinguals on a conflict task only, and this effect was very small. Further analyses showed broader effects on inhibitory control that were related to home language environment: Bilinguals whose parents spoke different languages outperformed bilinguals whose parents spoke the same language on both the conflict task and a delay of gratification task.

This paper has two major objectives: (1) to summarise Processability Theory, a processing-oriented approach to explaining language development and (2) to utilise this theory in the comparison of development in LI and L2 acquisition. Proponents of the Fundamental Difference Hypothesis (between L1 and L2) assume that L1 development can be explained with reference to Universal Grammar (UG) which, in their view, is inaccessible to L2 learners. Instead, they claim that a second language develops on the basis of language processing strategies.

I will show that the fundamentally different developmental paths inherent in first and second language acquisition can both be explained on the basis of the same language processing mechanics (as specified in Processability Theory). I will demonstrate that the developmental differences between L1 and L2 are caused by the qualitatively different early structural hypotheses which propagate through the acquisition process. The concept of “propagation of structural features” will be viewed as “generative entrenchment,” a logical-mathematical concept, which has proved to be highly productive in examining other kinds of developmental processes.

Second language acquisition studies can contribute to the body of research on the influence of language on thought by examining cognitive change as a result of second language learning. We conducted a longitudinal study that examined how the acquisition of Spanish grammatical gender influences categorization in native English-speaking adults. We asked whether learning the grammatical gender of Spanish affects adult native English speakers' attribution of gender to inanimate objects. College students enrolled in beginning Spanish participated in two tasks repeatedly (four times) throughout one academic year. One task examined their acquisition of grammatical gender. The other examined their categorization of inanimate objects. We began to observe changes in participants' grammatical gender acquisition and in categorization after ten weeks of Spanish instruction. Results indicate that learning a second language as an adult can change the way one categorizes objects. However, the effect of Spanish grammatical gender was more limited in Spanish learners than in native Spanish speakers; it was not observed for all kinds of objects nor did it increase with learners' proficiency, suggesting that adults learning Spanish reach a plateau beyond which changes in categorization do not occur.

A DST (Dynamic Systems Theory) characterization of L2 acquisition as an emergent process marks the coming of age of SLA research. It is an important theoretical maturation in that it brings together the many factors that interact in the complex system of language, learning, and use. It is an approach that has been budding for some time (Elman et al., 1996; Larsen-Freeman, 1997; MacWhinney, 1997; Ellis, 1998, 2003; Herdina and Jessner, 2002; Ellis and Larsen-Freeman, 2006), and recent symposia at AILA 2005, TESOL 2006 and AAAL 2006 conferences, and special issues in Applied Linguistics (2006) and here leave us heady with the scent of its blossom. What of fruition; what harvest shall we reap?

This issue of Bilingualism: Language and Cognition is about convergence, a type of language change that is contact-induced and results in greater similarity between two languages that are in contact with each other. In Backus (forthcoming), I have attempted an overview of contact-induced language change, focusing on causal factors, on mechanisms of change, and on the actual changes. In this conclusion, I will try to give convergence its rightful place in this general typology, referencing the contributions to this volume where appropriate.

This study compares mastery of gender assignment and agreement in Italian by adult Italian–German bilinguals who have acquired two languages simultaneously (2L1), and by adult German highly proficient second language learners (L2ers) of Italian. Our data show that incompleteness in bilingual acquisition and in second language (L2) acquisition primarily affects gender assignment: the categorization of nouns and the interpretable gender feature are subject to vulnerability in the two modalities of acquisition. Overall, mastery of morpho-syntax (i.e., gender agreement) was nearly native-like for both groups of speakers, suggesting that uninterpretable features are unlikely to be subject to vulnerability in the heritage language of adult bilingual speakers and can be acquired in adult L2 acquisition. Deviances from the target in gender assignment and, to a lesser extent, in gender agreement are attributed to both language-internal (i.e., language) and language-external factors (i.e., amount of input).

The present article investigates the acquisition of the pronominal systems by French and Italian monolingual children and by bilingual German–French and German–Italian children, demonstrating a stable asymmetry: object and reflexive clitics are acquired later than nominative clitics and strong subject and object pronouns. We will widen the scope of former investigations to include the acquisition of strong pronouns and argue that the observed asymmetry can be accounted for if we combine the external (categorial status) and internal syntax of pronouns (internal structure). In particular, we argue for the relevance of the absence/presence of a nominal layer (N-layer) in the internal structure of a pronoun. This approach can account for the observation that pronouns containing an N-layer, i.e., strong subject pronouns, subject clitics and strong object pronouns, are acquired simultaneously and earlier than pronouns which lack the N-layer, i.e., object clitics and reflexive clitics.

This study analyzes gender assignment in Spanish–Basque mixed nominal constructions with nouns in Basque (a language that lacks gender) and determiners in Spanish (a language that marks gender) by using a multi-task approach: (i) naturalistic data, (ii) an elicitation task, and (iii) an auditory judgment task. Naturalistic data suggest cross-language effects under which a morphological marker of Basque (-a determiner) is interpreted as a morphophonological expression of gender marking in Spanish. A preference for feminine determiners was observed in the judgment task, which differs from the masculine default trend observed in Spanish–English bilinguals (Jake, Myers-Scotton & Gross, 2002). Our results point to feminine gender as default in Spanish–Basque mixed DPs, indicating that the resources that bilinguals use for gender assignment can be different from those of monolinguals. We argue that this is an outcome of interacting processes which take place at the interfaces (lexicon, phonology, morphosyntax) of both languages, resulting in cross-language effects.

Building on our earlier analysis of the factorial structure of bilingualism for young adults obtained from the Language and Social Background Questionnaire (LSBQ; Anderson, Mak, Keyvani Chahi & Bialystok, 2018), we analyzed responses from 675 children and 125 older adults to a similar questionnaire. Three factors accounting for 74% of the variance emerged in the analysis of children's responses: Adult Language in the Home, Non-English use for Media, Non-English use with Siblings. There were also three factors that explained the responses of older adults that accounted for 79% of the variance: Non-English Use, Non-English Proficiency, and English Proficiency. Therefore, bilingual experience is captured by different factors at different points in the lifespan. These results are discussed in conjunction with the earlier results from young adults and the implications for understanding bilingualism across the lifespan.

Although the extant literature provides robust evidence of the influence of language exposure and socioeconomic status (SES) on language acquisition, it is unknown how sensitive the early receptive vocabulary system is to these factors. The current study investigates effects of minimal second language exposure and SES on the comprehension vocabulary of 16-month-old children in the language in which they receive the greatest exposure. Study 1 revealed minimal second language exposure and SES exert significant and independent effects on a direct measure of vocabulary comprehension in English-dominant and English monolingual children (N = 72). In Study 2, we replicated the effect of minimal second language exposure in Spanish-dominant and Spanish monolingual children (N = 86), however no effect of SES on vocabulary was obtained. Our results emphasize the sensitivity of the language system to minimal changes in the environment in early development.

This study examined the effect of second language (L2) age of acquisition and amount of experience on the production of word-final stop consonant voicing by adult native Korean learners of English. Thirty learners, who differed in amount of L2 experience and age of L2 exposure, and 10 native English speakers produced 8 English monosyllabic words ending in voiced and voiceless stops. These productions were presented to 10 English listeners for perceptual judgment and subjected to acoustic analyses to determine how well learners produced vowel duration and closure (stop gap) duration, two cues to stop consonant voicing. Results revealed that even learners with 10 years of L2 experience did not always produce stop consonant voicing accurately, that learners' age of acquisition influenced their production of both cues, that vowel duration was easier to learn than closure duration, and that English listeners used both these cues in their judgments of production accuracy.

The present study investigates the influence of word category on naming performance in two populations: bilingual and monolingual children. The question is whether and, if so, to what extent monolingual and bilingual children differ with respect to noun and verb naming and whether a noun bias exists in the lexical abilities of bilingual children. Picture naming of objects and actions by Russian–German bilingual children (aged 4–7 years) was compared to age-matched monolingual children. The results clearly demonstrate a naming deficit of bilingual children in comparison to monolingual children that increases with age. Noun learning is more fragile in bilingual contexts than is verb learning. In bilingual language acquisition, nouns do not predominate over verbs as much as is seen in monolingual German and Russian children. The results are discussed with respect to semantic-conceptual aspects and language-specific features of nouns and verbs, and the impact of input on the acquisition of these word categories.

The aim of the current study was to examine the effects of bilingualism on letter and category fluency tasks. Participants were 1,600 monolingual and bilingual children from three cities in Iran: Tehran (Persian monolinguals), Tabriz (Turkish–Persian bilinguals), and Sanandaj (Kurdish–Persian bilinguals). We separately presented nine Persian letters and thirty-one categories to the participants, and asked them to generate as many words as possible using each of these initial letters and categories within a maximum of three minutes. Bilingual children generated more words than monolingual children in the letter fluency task; this effect was more pronounced in Grade 1 and for Turkish–Persian bilinguals. However, Persian monolinguals generated significantly more words than both bilingual groups in the category fluency task. Thus, bilingualism can be of both advantage and disadvantage, and produce a dissociative effect. We discuss the results on the basis of the specific nature and different cognitive demands of letter and category fluency tasks. We suggest that the degree of language proficiency of bilinguals should be considered as an important variable in future research on bilingualism.

Recent research shows that speakers with different first languages perceive various cognitive domains in different ways and that bilinguals’ conceptualization patterns are affected by the concepts of both languages. The present study extends Choi and Bowerman (1991) by examining the categorizations of spatial concepts in adult Korean–English bilinguals. Using similarity judgments, the study compares the conceptualization patterns of “put in” and “put on” by Korean–English bilinguals and Korean and English monolinguals. Results indicated significant differences between the monolingual and bilingual groups, demonstrating the process of convergence of the two languages in the bilingual mind. Regression analyses also revealed that bilinguals’ conceptualizations are largely influenced by English proficiency and frequency of Korean use. These findings provide evidence of conceptual restructuring, supporting the claim of previous research that bilinguals’ conceptualization patterns are susceptible to their language experience.

The present study aims to understand which factors contribute to different patterns of use of referring expressions by bilingual children, by considering the triangulation between language experience and proficiency, executive functions and cross-linguistic effects. We analyze reference use in Greek in the context of a narrative elicitation task as performed by 125 children of different language combinations, including Greek–Albanian, Greek–English and Greek–German. We calculate, for each child, an index of language experience that combines a proficiency measure with background questionnaire information. After identifying the occurrences of underinformative (underspecified) and overinformative (overspecified) referring expressions in the production of each child, we investigate to what extent each pattern of reference use is affected by language experience, cross-linguistic effects and executive functions. The study aims to shed some new light on the nature of overspecification and underspecification in bilingual reference production and, more in general, to model variation in reference use among bilingual children.

We investigated trial-by-trial and cumulative cross-language effects of structural priming and verb bias on L1 and L2 dative syntactic choices (e.g., ‘boy-give-ball-to-girl’ [PO structure] vs. ‘boy-give-girl-ball’ [DO structure]). Dutch-dominant Dutch–English bilinguals listened to a prime sentence with a DO or PO structure in one language and then described a picture in the other language, using verbs that varied in their bias towards the PO or DO structure in Dutch and English. We found effects of cross-language structural priming and verb bias on syntactic choice, some of which were influenced by the participants’ language dominance. In addition, we found cumulative forms of structural priming, leading to cross-language priming effects between experimental blocks. We discuss these results in terms of models on the representation of lexical and syntactic information in bilinguals, and point out how the observed effects can be related to experience-based mechanisms of language use and contact-induced language change.