Language mixing is a common phenomenon in the language input of bilingual children. However, the relation between the frequency of parental language mixing and children’s language development remains unclear. The present study investigates the relation between language mixing as observed in daylong audio recordings (LENA) and as reported by parents in the questionnaire for Quantifying Bilingual Experience (Q-BEx) and children’s language outcomes in the majority and minority language. Participants were 52 3-to-5-year-old Polish-Dutch and Turkish-Dutch children in the Netherlands and Bayesian informative hypothesis evaluations were applied. In 14 out of 15 regression analyses, the LENA and Q-BEx measures yielded similar associations with children’s language outcomes. Parental language mixing was not related to majority language outcomes, but a negative relation was found with expressive vocabulary in the minority language. Longitudinal studies are needed to pinpoint the directionality of this negative relation.

The main aim of this study, which presents the Slovenian adaptation of the Macarthur-Bates Communicative Development Inventory CDI–III, was to investigate the characteristics of language development in monolingual Slovenian-speaking children aged 30–48 months. In addition, we examined the relationships between different measures of child language assessed by the CDI–III, namely vocabulary, grammar and metalanguage. The sample comprised 301 children whose language was assessed by their parents using the Slovenian version of the CDI–III. The results indicate that language development at this age continues to progress relatively quickly, particularly in terms of children’s metalinguistic abilities, although there are large individual differences in language ability between children of the same age. The findings also indicate that some of the pre-existing relationships established between the different domains of infant and toddler language ability persist into early childhood, with vocabulary emerging as an important predictor of children’s grammar.

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 investigates how phonological competition affects real-time spoken word recognition in deaf and hard of hearing (DHH) preschoolers compared to peers with hearing in the normal range (NH). Three-to-six-year olds (27 with NH, 18 DHH, including uni- and bilateral hearing losses) were instructed to look at pictures that corresponded to words alongside a phonological competitor (e.g., /bin-pin/) vs. an unrelated distractor (e.g., /toy-bed/). Phonological competitors contrasted in either voicing or place of articulation (PoA), in the onset or coda of the word. Relative to peers with NH, DHH preschoolers showed reduced looks to target in reaction to the spoken words specifically when competition was present. DHH preschoolers may thus, as a group, experience increased phonological competition during word recognition. There was no evidence that phonological properties (voicing vs. PoA, or onset vs. coda) differentially impacted word recognition.

Irony comprehension requires going beyond literal meaning of words and is challenging for children. In this pre-registered study, we investigated how teaching metapragmatic knowledge in classrooms impacts written irony comprehension in 10-year-old Finnish-speaking children (n = 41, 21 girls) compared to a control group (n = 34, 13 girls). At pre-test, children read ironic and literal sentences embedded in stories while their eye movements were recorded. Next, the training group was taught about irony, and the control group was taught about reading comprehension. At post-test, the reading task and eye-tracking were repeated. Irony comprehension improved after metapragmatic training on irony, suggesting that metapragmatic knowledge serves an important role in irony development. However, the eye movement data suggested that training did not change the strategy children used to resolve the ironic meaning. The results highlight the potential of metapragmatic training and have implications for theories of irony comprehension.

Speakers consider their listeners and adjust the way they communicate. One well-studied example is the register of infant-directed speech (IDS), which differs acoustically from speech directed to adults. However, little work has explored how parents adjust speech to infants across different contexts. This is important because infants and parents engage in many activities throughout each day. The current study tests whether the properties of IDS in English vary across three in-lab tasks (sorting objects, free play, and storytelling). We analysed acoustic features associated with prosody, including mean fundamental frequency (F0, perceived as pitch), F0 range, and word rate. We found that both parents’ pitch ranges and word rates varied depending on the task in IDS. The storytelling task stood out among the tasks for having a wider pitch range and faster word rate. The results depict how context can drive parents’ speech adjustments to infants.

A growing body of research has found that talking to young children is positively associated with language outcomes. However, there is tremendous heterogeneity in the design of these studies, which could potentially affect the strength and reliability of this association. The present meta-analysis, comprising 4760 participants across 71 studies, goes beyond prior research by including: 1) more recent studies, 2) non-English-speaking populations, 3) more fine-grained categorization of measures of input, 4) additional moderators, and 5) a multilevel model design allowing us to consider multiple effect sizes per study. We find a moderate association between input and outcomes (R2=0.04-0.07) across four input measures, with some evidence of publication bias. We find no differences in effect size across any of the input measures. Child age and study duration moderated some effects of input. Our findings suggest that language input-outcome associations remain robust but modest across a multitude of contexts and measures.

Mental state verbs (MSVs) describe people’s knowledge, thoughts, feelings and desires, and develop through early childhood. This study used a cross-sectional design and a parental questionnaire to describe the developmental process of MSV use by exploring different trajectories of semantic categories within MSVs. One-hundred-fourteen typically developing, Hebrew-speaking children, ages 1;6–10;0 participated in the study. Their parents completed a questionnaire developed for the current study, which contains MSVs from five semantic categories: desire, emotion, cognition, perception, and psychological, plus physical verbs as a control category. Among them, 58 children (ages 3;2–10;0 years) participated in a narrative task that prompted production of MSVs. Results showed scores increased with age from early childhood to elementary school, demonstrating prolonged development of using MSVs. A minor advantage for girls was found in the younger ages compared with boys. Both, boys and girls had different developmental trajectories for physical, physiological, and desire verbs compared with cognition and emotion verbs. The correlation found between the questionnaire scores and the narrative task supports the validity of the questionnaire for assessing MSV use in children. The results are explained by the complex syntactic structure and abstract meaning of MSVs.

This retrospective study provides insights on linguistic development in exceptional circumstances assessing 378 children (between 2;6 and 3;6) who lived their first years during the COVID-19 pandemic and comparing it with normative data collected before this period (CDI-III-PT; Cadime et al., 2021). It investigates the extent to which linguistic development was modulated by a complex set of factors, including sex, maternal education, book reading, language-promoting practices, COVID-19 infection, parental stress and sleeping problems, considering three periods (during lockdowns, out of lockdowns and at present). The results show a substantial negative effect of the pandemic on both lexical and syntactic development. Considering individual variation, structural equation modelling unveiled a complex scenario in which age, sex, book reading, language-promoting practices, sleeping problems and COVID-19 infection showed a direct effect on linguistic development. Maternal education and parental stress had an indirect effect on children’s language, mediated by book reading and sleeping problems, respectively.

Alexithymia (difficulties identifying and describing feelings) predicts increased risks for psychopathology, especially during the transition from childhood to adolescence. However, little is known of the early contributors to alexithymia. The language hypothesis of alexithymia suggests that language deficits play a primary role in predisposing language-impaired groups to developing alexithymia; yet longitudinal data tracking prospective relationship between language function and alexithymia are scarce. Leveraging data from the Surrey Communication and Language in Education cohort (N = 229, mean age at time point 1 = 5.32 years, SD = 0.29, 51.1% female), we investigated the prospective link between childhood language development and alexithymic traits in adolescence. Results indicated that boys with low language function at ages 4–5 years, and those who later met the diagnostic criteria for language disorders at ages 5–6 years, reported elevated alexithymic traits when they reached adolescence. Parent-reported child syntax abilities at ages 5–6 years revealed a dimensional relationship with alexithymic traits, and this was consistent with behavioral assessments on related structural language abilities. Empirically derived language groups and latent language trajectories did not predict alexithymic traits in adolescence. While findings support the language hypothesis of alexithymia, greater specificity of the alexithymia construct in developmental populations is needed to guide clinical interventions.

We present an exploratory cross-linguistic analysis of the quantity of target-child-directed speech and adult-directed speech in North American English (US & Canadian), United Kingdom English, Argentinian Spanish, Tseltal (Tenejapa, Mayan), and Yélî Dnye (Rossel Island, Papuan), using annotations from 69 children aged 2–36 months. Using a novel methodological approach, our cross-linguistic and cross-cultural findings support prior work suggesting that target-child-directed speech quantities are stable across early development, while adult-directed speech decreases. A preponderance of speech from women was found to a similar degree across groups, with less target-child-directed speech from men and children in the North American samples than elsewhere. Consistently across groups, children also heard more adult-directed than target-child-directed speech. Finally, the numbers of talkers present in any given clip strongly impacted children’s moment-to-moment input quantities. These findings illustrate how the structure of home life impacts patterns of early language exposure across diverse developmental contexts.

In the current pre-registered study, we examined the associations between shared book reading, daily screen time, and vocabulary size in 1,442 12- and 24-month-old Norwegian infants. Our results demonstrate a positive association between shared reading and vocabulary in both age groups, and a negative association between screen time and vocabulary in 24-month-olds. Exploratory analyses revealed that the positive relationship between shared reading and expressive vocabulary in 12-month-olds was stronger in lower SES groups, suggesting that shared reading may act as a compensatory mechanism attenuating potentially impoverished learning environment and parent-infant interactions in low-SES families.

This research investigated the impact of the number of talkers with whom children engage in daily conversation on their language development. Two surveys were conducted in 2020, targeting two-year-olds growing up in Japanese monolingual families. Caregivers reported the number of talkers in three age groups and children’s productive vocabulary via questionnaires. The results demonstrated significant effects of variability in talkers in fifth grade or above in Study 1 (N = 50; male = 23; r = .372) and in adult talkers in Study 2 (N = 175; non-nursery going; male = 76; r = .184) on children’s vocabulary development, after controlling for language exposure time and demographic variables. Possible mediating factors are discussed. This research extends previous findings from immigrant bilingual children to monolingual speakers in Japan, suggesting the potential contribution of available talkers other than caregivers in conversational environments.

Internal state language (ISL) research contains knowledge gaps, including dimensionality and predictors of growth, addressed here in a two-aim study. Parent-reported expressive language from N = 6,373 monolingual, English-speaking toddlers (Mage = 23.5mos, 46% male, 57% white) was collected using cross-sectional and longitudinal data in WordBank. Exploratory and confirmatory factor analyses suggested a best-fitting one-factor model of ISL. The single-factor model of ISL was then submitted to hierarchical linear modeling to evaluate predictors of ISL development. Age 2 ISL production was predicted by child sex, wherein females outperform males, and maternal education, wherein higher education contributes to higher ISL. Only maternal education emerged as a significant predictor of ISL growth. These results provide support to theory suggesting a unitary construct of ISL, as opposed to considering ISL as categorical, and further illustrate linear growth through the second postnatal year that varies as a function of child sex and maternal education.