Although family factors are considered important for children’s language acquisition, the evidence comes primarily from affluent societies. Thus, this study aimed to examine the relations between family factors (family’s socioeconomic status [SES], home literacy activities, access to print resources, and parental beliefs) and children’s vocabulary knowledge in both urban and rural settings in China. Data from 366 children (urban group: 109, 4.85 years; rural group: 257, 4.89 years) were collected. Results showed that whereas family’s SES significantly predicted access to print resources and children’s vocabulary knowledge in the rural group, parental beliefs directly predicted children’s vocabulary knowledge in the urban group. Multigroup analysis showed that the associations of family’s SES and access to print resources with children’s vocabulary knowledge were stronger in the rural group than in the urban group. Our findings highlight the importance of considering contextual settings when conceptualising the role of family factors in children’s language acquisition.

Children are known to derive more implicatures when the required alternative is made salient through contrast or when it is made contextually relevant through a story or a Question Under Discussion. We investigated the exclusivity implicature of three disjunctions (sau “or”, sau… sau, and fie…fie “either…or”) in child Romanian, an understudied language in the previous literature. Three experiments reveal that the mere presence of the stronger alternative, that is, simply hearing unrelated conjunctive statements in the course of the experiment, is not enough to boost implicatures. Rather, implicatures increase as a result of both access to alternatives and contextual relevance (expressed through conjunctive questions such as Did the hen push the train and the boat?). Interestingly, the boost in implicatures was observed only for sau-based disjunctions, not for fie…fie, which we conjecture may be due to children treating the latter as ambiguous between disjunction and conjunction.

How do children learn the language-to-concept mappings within the domain of Mechanical Support – a spatial domain involving varied and complex force-dynamic relations between objects based on specific mechanisms (stickiness, clips, etc.)? We explore how four- and six-year-olds, and adults encode dynamic events and static configurations of Mechanical Support via attachment (picture put on a door). Participants viewed spatial configurations (Experiment 1 – in dynamic events or Experiment 2 – in static states) and were then prompted with the question, “Can you tell me what my sister did with my toy?” Children and adults used lexical verbs, and the visibility of the mechanism influenced the type of verb used. Also, whereas children preferentially used Orientation Verbs (e.g., “hang”), adults preferentially used Verbs of Attaching (e.g., “tape,” “stick”). Our findings shed light on how children acquire mechanical support language and the linguistic and cognitive constraints involved.

This study will investigate how children acquire the option to drop the subject of a sentence, or null subjects (e.g., “Tickles me” instead of “He tickles me”). In languages that do not permit null subjects, children produce sentences with null subjects from 1 to 3 years of age. This non-adultlike production has been explained by two main accounts: first, the null subject sentences may accurately reflect the children’s linguistic knowledge, that is, a competence account. Alternatively, they may result from immature processing resources, therefore underestimating children’s competence, that is, a performance account. We will test the predictions of these accounts by using a central fixation preference procedure and elicited imitation to measure children’s comprehension and production, respectively, in monolingual 19- to 28-month-olds acquiring English (a non-null subject language) and Italian (a null subject language). The results will shed light on acquisition across languages, and the features that provide evidence to a learner.

Previous research indicates that strong right-hand preference predicts performance in other skills, such as vocabulary size and executive function (EF). The purpose of this study was to assess the relationship between these functions, as well as social competence (SC), in a sample of preschool children. We used parent questionnaires and/or tabletop assessments to measure hand preference, fine motor skills, language, EF, and SC in 81 three- to five-year-old children. The results strengthened the evidence of a connection between right-hand use for pointing and vocabulary performance but indicated that right-hand use was not related to EF or SC. Further, the findings revealed a reciprocal connection between vocabulary and SC as well as EF and SC, but not vocabulary and EF. We discuss the implications of these connections for early childhood development.

By comparing infant-directed speech to spouse- and dog-directed talk, we aimed to investigate how pitch and utterance length are modulated by speakers considering the speech context and the partner’s expected needs and capabilities. We found that mean pitch was modulated in line with the partner’s attentional needs, while pitch range and utterance length were modulated according to the partner’s expected linguistic competence. In a situation with a nursery rhyme, speakers used the highest pitch and widest pitch range with all partners suggesting that infant-directed context greatly influences these acoustic features. Recent findings showed that these speakers expressed more intense positive emotions towards their infants and spouses than towards their dogs. Our results revealed different patterns, leading us to conclude that these acoustic features are not simple by-products of emotional speech. Instead, they are dynamically and functionally used in accordance with the speech context and the audience’s expected needs and capabilities.

Research on the language acquisition of deaf individuals who are exposed to accessible linguistic input at a variety of ages has provided evidence for a sensitive period of first language acquisition. Recent studies have shown that deaf individuals who first learn language after early childhood, late first-language learners (LL1), do not comprehend reversible Subject-Verb-Object (SVO) sentences. The present study analyzed 478 signed productions elicited with pictures depicting simple events with one or two arguments by 28 signers. The argument order patterns of native signers converged with one another and the word order patterns of American Sign Language (ASL). By contrast, the ordering patterns of the LL1 signers did not converge with one another or with the patterns of the native signers. This indicates that early childhood is a period of heightened sensitivity to basic word order and may help explain why complex structures are difficult for LL1 signers to learn.

Adults rate the speech of children assigned male at birth (AMAB) and assigned female at birth (AFAB) as young as 2.5 years of age differently on a scale of definitely a boy to definitely a girl (Munson et al., 2022), despite the lack of consistent sex dimorphism in children’s speech production mechanisms. This study used longitudinal data to examine the acoustic differences between AMAB and AFAB children and the association between the acoustic measures and perceived gender ratings of children’s speech. We found differences between AMAB and AFAB children in two acoustic parameters that mark gender in adult speech: the spectral centroid of /s/ and the overall scaling of resonant frequencies in vowels. These results demonstrate that children as young as 3 years old speak in ways that reflect their sex assigned at birth. We interpret this as evidence that children manipulate their speech apparatus volitionally to mark gender through speech.

This study evaluates how language exposure and mothers’ language dominance relate to infants’ early bilingual vocabulary development in a low-socioeconomic status (SES) sample from an understudied population: Mexican Indigenous bilinguals. Thirty-two mother–child dyads participated. All mothers were bilingual speakers of Spanish and one of Mexican Indigenous languages, including Zapotec, Mixtec, and Otomi. Infants’ (between 16 and 37 months) vocabulary size was estimated in both languages using the Mexican Spanish version of the MacArthur-Bates CDI II. Infants’ language exposure, mothers’ bilingual profile, and their SES were estimated on numerical scales. The results of Spearman correlations showed infants’ vocabulary size in Spanish grows with age, while their vocabulary in the Indigenous language depends on relative language exposure. Mothers’ language dominance correlated with Indigenous language exposure and infants’ vocabulary size in the Indigenous language. These findings are discussed in the context of early bilingual vocabulary acquisition in speakers of minority languages.

This study aimed to explore the effect of various feedback types on word learning in preschool children, with consideration of the word’s morpho-phonological structure. Sixty-three five-year-old children participated in three sessions of learning artificial words derived from pseudo-roots in Hebrew, with half constructed using established morpho-phonological patterns. Participants received either no feedback, verification feedback, corrective feedback, or verification plus corrective feedback. The training encompassed word identification and production. Accuracy and reaction time (RT) were measured. The results indicated that corrective feedback produced the highest accuracy and fastest RTs. Providing verification feedback led to improved performance compared to no feedback. While words with existing morpho-phonological patterns were learned more efficiently, the positive impact of corrective feedback remained consistent across both word types. These findings offer practical implications for optimizing word learning conditions, highlighting the importance of corrective feedback in word learning, and more broadly, aligning the feedback type to the learning task.

Children’s acquisition of variation in the target language depends on a number of factors not yet well understood. This study probes the acquisition of morphological variation in two unrelated languages, Croatian (Slavic) and Estonian (Finnic), focussing on parallel forms of a lexeme expressing a single grammatical category (a phenomenon known as morphological overabundance). We conducted a cross-linguistic elicitation experiment with 140 monolingual, typically developing children aged 3;0 to 6;11 (80 learning Croatian, 60 Estonian). We elicited genitive plural forms in Croatian and partitive plural in Estonian, with lexemes which either are invariant or allow more than one form. Children in both languages were less accurate with lexemes with parallel forms, indicating that the morphological variation hindered acquisition. Pattern type frequency was found to affect accuracy in both languages. Children’s choice between two parallel forms was unaffected by age, but significant language-specific differences emerged.

It is important to assess learning in both familiar and unfamiliar conditions to determine the extent of learning generalisation. In this study, we evaluated parent language outcomes of LENA Start™, a parent-implemented intervention, using distal measures derived from a parent–child free play interaction.

Forty-four parents and their child (mean: 20.8 months) participated in LENA Start™ or early childhood education curriculum intervention, in either English (n = 34) or Spanish (n = 10). We completed between- and within-group analyses using language and communication behaviour measures derived from parent–child interactions elicited outside the home with researcher-supplied materials (i.e., distal measures).

Group comparisons revealed significant differences on a subset of behavioural measures. Spanish-speaking parents in the LENA Start™ group demonstrated significant gains on three measures. While LENA Start™ has been associated with parent gains on proximal language measures, the results of this study reveal limited generalisation of skills based on distal measures.

The current study examined the relationship between interest, the home environment, and young Chinese children’s development of English as a second/foreign language in Hong Kong. Two hundred and seventy-four Hong Kong kindergartners were assessed on their interest in learning English and their English language skills (i.e., expressive and receptive vocabulary). Their parents completed questionnaires eliciting family socio-economic status, parental beliefs, and home learning environment. The results indicated that (1) interest was related to children’s English language abilities after controlling for children’s gender, non-verbal intelligence, and kindergarten type; (2) parents’ beliefs about their child’s English ability and self-efficacy were related to children’s interest in learning English; and (3) interest uniquely contributed to children’s English language ability in the home environment. The present findings provide evidence of the active role that children play in their second/foreign language development and highlight the significant influence of parental beliefs on children’s interest in learning English.

This longitudinal study investigates the changes in bilingual oral language proficiency and home language and literacy practices of young Chinese American and Mexican American dual language learners (DLLs) before and during the COVID-19 pandemic. Given that DLLs represent a significant portion of young children in the U.S., often facing socioeconomic challenges, understanding their language development is crucial. The pandemic’s considerable impact on the educational trajectories of low-income immigrant communities is of particular concern. The sample comprised 132 DLLs (41 Mexican Americans and 91 Chinese Americans) from low-income immigrant families. Data on oral language proficiency in English and the home language and home literacy practices were collected before the pandemic and again 1.5 years later. Despite school closures, both groups showed improved oral language proficiency and shifts in home literacy practices over time. This study reveals distinct relationships between home literacy practices and oral language proficiency in the two immigrant groups.

We investigate the effects of age and first language (L1) on the acquisition of verb morphology in L2 English by Chinese and Russian children learning English as a foreign language in EFL schools in Shanghai and Moscow. We tested children 5 years after they started their EFL classes and considered two groups in each country: one group started EFL classes at the age of 4 and was tested at the age of 9, while the other group started at 7 and was tested at 12. We assessed the production of 3SG-agreement and past tense using two elicited production tasks (TEGI). Our results show that later starters consistently outperform earlier starters. Unexpectedly, Chinese children showed higher accuracy with 3SG-agreement than their Russian counterparts. Finally, learners were more accurate with regular past tense than 3SG-agreement.

Children’s speech becomes longer and more complex as they develop, but the reasons for this have been insufficiently studied. This study examines how changing linguistic choices in children are linked to interactive factors by analysing Who-question sequences in Japanese child–caregiver conversations. The interactive factors in focus are progressivity and balanced joint activity, which are core aspects of conversational interaction. Our analysis reveals that as children respond to Who-questions, their responses grow in length and multifunctionality. This growth is positively associated with progressivity, namely a quicker completion of the question sequence, and reduced functional load in the interlocutor’s contributions, resulting in more balanced joint activity. These findings suggest that children adapt their linguistic choices by observing and aligning them with their interactive goals in conversational sequences.

This study investigates four factors (age, sex, SES, and bilingualism) influencing children’s language attitude (LA) development. We examine LAs in monolingual (N = 46) and bilingual (N = 71) children (59–143 months) living in France using a matched guise experiment where the children evaluated normative and non-normative variants of five linguistic constructions in French. Using a mixed-effects model, we show that children’s preferences for normative variants increase with age, and each linguistic construction documented is subject to different attitudinal timeframes. The probabilities of preferring the normative variants are significantly higher for monolingual girls than for bilingual girls. Whilst lower-class and upper-class children’s LAs are similar, low-to-middle-class children’s responses are more random, which may illustrate the potential effects of linguistic insecurity. We discuss how the children’s construction of the sociocognitive representations of linguistic variation could be explained by considering children’s language exposure and experiences of socialisation.

We present a simulation study based on a cognitive architecture that unifies various early language acquisition phenomena in laboratory and naturalistic settings. The model adaptively learns procedures through trial-and-error using general-purpose operators, guided by learned contextual associations to optimise future performance. For laboratory-based studies, simulated preferential focusing explains the delayed behavioural onset of statistical learning and the possible age-related decrease in algebraic processing. These findings suggest a link to continuous, implicit learning rather than explicit strategy acquisition. Moreover, procedures are not static but can evolve over time, and multiple plausible procedures may emerge for a given task. Besides, the same model provides a proof-of-concept for word-level phonological learning from naturalistic infant-directed speech, demonstrating how age-related processing efficiency may influence learning trajectories implicated in typical and atypical early language development. Furthermore, the artile discusses the broader implications for modelling other aspects of real-world language acquisition.

Children acquire vocabulary at different growth rates. The aim of this study was to identify subgroups of different vocabulary trajectories in a community sample of L1 German-speaking children aged 1;6 to 3;0 to enlarge the understanding of vocabulary trajectories. Parents filled out vocabulary checklists at four measurement times, each six months apart. Growth mixture modelling was used to naturally determine latent classes of observed vocabulary growth curve patterns. Six distinct trajectories of vocabulary growth were identified and characterised. Children’s (N=198) vocabulary abilities were divided into the following subgroups: “far above average” (2.0%), “above average” (6.6%), “typical” (70.2%), “below average” (14.1%), “early below average" but caught up with their peers over time (5.6%), and “far below average” (1.5%). Socioeconomic status differed significantly between subgroups.

We explored whether bilingual toddlers make use of semantic and phonological overlap between their languages to learn new words. We analysed cross-sectional and longitudinal CDI data on the words understood and produced by 1.0 to 3.0-year-old bilingual toddlers with English and one additional language. Cognates were more likely to be understood and produced compared to non-cognates. Cognate effects were modulated by whether the toddler knew the translation equivalent in the other language, highlighting that young learners are sensitive to the similarities across their languages. Additionally, exploratory analyses suggest that children with smaller vocabularies rely more on translation equivalents to support the acquisition of difficult words. Children with larger vocabulary sizes exhibited no preference for translation equivalents in comprehension, and a preference for new concepts in production. The rapid acceleration of vocabulary growth in the second year of life may explain this developmental change in translation equivalent preference.