Forty-eight toddlers participated in a word-learning task to assess gesture input on mapping nonce words to unfamiliar objects. Receptive fast mapping and expressive naming for target object-word pairs were tested in three conditions – with a point, with a shape gesture, and in a no-gesture, word-only condition. No statistically significant effect of gesture for receptive fast-mapping was found but age was a factor. Two year olds outperformed one year olds for both measures. Only one girl in the one-year-old group correctly named any items. There was a significant interaction between gesture and gender for expressive naming. Two-year-old girls were six times more likely than two-year-old boys to correctly name items given point and shape gestures; whereas, boys named more items taught with the word only than with a point or shape gesture. The role of gesture input remains unclear, particularly for children under two years and for toddler boys.

We examined whether and how the degree of meaning overlap between morphologically related words influences sentence plausibility judgment in children. In two separate studies with kindergarten and second-graders, English-speaking and French-speaking children judged the plausibility of sentences that included two paired target words. Some of these word pairs were morphologically related, across three conditions with differing levels of meaning overlap: low (wait-waiter), moderate (fold-folder) and high (farm-farmer). In another two conditions, word pairs were related only by phonology (rock-rocket) or semantics (car-automobile). Children in both ages and languages demonstrated higher plausibility scores as meaning overlap increased between morphologically related words. Further, kindergarten children rated sentences that included word pairs with phonological overlap as more plausible than second-grade children, while second-grade children rated those with high meaning overlap as more plausible than kindergarten children. We interpret these findings in light of current models of morphological development.

The current study sought to investigate whether word properties can facilitate the identification of developmental language disorder (DLD) in sequential bilinguals by analyzing properties in nouns and verbs in L2 spontaneous speech as potential DLD markers. Measures of semantic (imageability, concreteness), lexical (frequency, age of acquisition) and phonological (phonological neighbourhood, word length) properties were computed for nouns and verbs produced by 15 sequential bilinguals (5;7) with DLD and 15 age-matched controls with diverse L1 backgrounds. Linear mixed modelling revealed a significant interaction of group and word category on phonological neighbourhood values but no differences across imageability, concreteness, frequency, age of acquisition, and word length measures in spontaneous speech. Outcomes suggest that group-level differences may not be apparent at the word-level, due to the heterogeneous nature of DLD and potential similarities in production during early L2 acquisition.

This study investigates how Japanese-speaking children learn interactional dependencies in conversations that determine the use of un, a token typically used as a positive response for yes-no questions, backchannel, and acknowledgement. We hypothesise that children learn to produce un appropriately by recognising different types of cues occurring in the immediately preceding turns. We built a set of generalised linear models on the longitudinal conversation data from seven children aged 1 to 5 years and their caregivers. Our models revealed that children not only increased their un production, but also learned to attend relevant cues in the preceding turns to understand when to respond by producing un. Children increasingly produced un when their interlocutors asked a yes-no question or signalled the continuation of their own speech. These results illustrate how children learn the probabilistic dependency between adjacent turns, and become able to participate in conversational interactions.

Private speech is a cognitive tool to guide thinking and behavior, yet its regulatory use in atypical development remains equivocal. This study investigated the influence of task difficulty on private speech in preschool children with attention or language difficulties. Measures of private speech use, form and content were obtained while 52 typically developing and 25 developmentally at-risk three- to four-year-old children completed Duplo construction and card sort tasks, each comprising two levels of challenge. In line with previous research, developmentally at-risk children used less internalized private speech than typically developing peers. However, both typically developing and at-risk children demonstrated a similar regulatory private speech response to difficulty with no systematic evidence of group difference. This was captured by an increase in all utterances, reduced private speech internalization, and more frequent forethought and self-reflective content. Results support the hypothesis of delayed private speech internalization but not regulatory deviance in atypical development.

Voice onset time (VOT) of aspirated stop consonants is marked by variability and systematicity in adult speech production. The present study investigated variability and systematicity of voiceless aspirated stop VOT from 161 two- to five-year-old talkers of American English and Cantonese. Overall, many aspects of child VOT productions parallel adult patterns, the analysis of which can help inform our understanding of early speech production. For instance, VOT means were comparable between children and adults, despite greater variability. Further, across children in both languages, talker-specific VOT means were strongly correlated between [th] and [kh]. This correlation may reflect a constraint of “target uniformity” that minimizes variation in the phonetic realization of a shared distinctive feature. Therefore findings suggest that target uniformity is not merely a product of a mature grammar, but may instead shape speech production representations in children as young as two years of age.

In this preregistered, longitudinal study of early code-switching, 34 US-born, Spanish–English bilingual children were recorded with a bilingual family member at 2;6 and 3;6, in Spanish-designated and English-designated interactions. Children’s Spanish and English expressive vocabulary and their exposure to code-switching were measured through direct assessment and caregiver report. The children code-switched most frequently at speaker changes; within-turn and within-utterance codeswitching were rare. By 3;6, switches to English were significantly more frequent than switches to Spanish. At both ages, Spanish proficiency was a negative predictor of the frequency of switching to English, but children’s degree of English dominance uniquely explained additional variance. Thus, children appear to code-switch not merely to fill gaps in their weaker language but to maximize their expressive power. Neither individual differences in exposure to code-switching nor in the interlocutors’ language proficiency were consistently related to the children’s rate of code-switching.

This longitudinal study investigated how lexical restructuring can stimulate emerging bilingual children’s phonological awareness in their first (L1) and second (L2) languages. Sixty-two English (L1) – French (L2) bilingual children (Mage = 75.7 months, SD = 3.2) were taught new English and French word pairs differing minimally in phonological contrast. The results indicated that increasing lexical specificity in English mediated the relationship between English vocabulary and English phonological awareness both concurrently and longitudinally at the end of Grade 1. A longitudinal relationship was established among French vocabulary, French lexical specificity, and French phonological awareness at the end of Grade 1. Notably, cross-language transfer from English lexical specificity was a better predictor of development in French phonological awareness, especially for words that contained phonological contrasts that occurred in both languages. The results from this study highlight the phonological foundations of early literacy and extend the lexical restructuring hypothesis to emerging bilingual children.

Producing word-initial /s/-stop clusters can be a challenge for English-speaking pre-schoolers. For children with hearing loss (HL), fricatives can be also difficult to perceive, raising questions about their production and representation of /s/-stop clusters. The goal of this study was therefore to determine if pre-schoolers with HL can produce and represent the /s/ in word-initial /s/-stop clusters, and to compare this to their normal hearing (NH) peers. Based on both acoustic and perceptual analysis, we found that children with HL had little /s/-omission, suggesting that their phonological representation of these clusters closely aligns with that of their NH peers.

The study investigates whether Italian verbal inflectional morphology is associated with inhibitory control skills after controlling for receptive vocabulary and verbal working memory. A sample of Italian preschoolers aged 4;0 to 6;0 was assessed using a standardized inhibitory control task tapping two different inhibitory skills (response inhibition and interference suppression), and a morphological task requiring simple and complex inflections of verbs. The hierarchical multiple regression analyses showed that working memory and the interference suppression scores were significantly associated with complex inflections but not with simple inflections of the verbs.

Young children often make pragmatic assumptions when learning new words. For example, they assume that a speaker who uses different words intends to refer to different things – the so-called principle of contrast. We used a standard disambiguation task to explore whether children’s assumptions about contrast depend on how much words differ. Three- to 6-year-olds heard pairs of words that differed in terms of the number, position, and types of phonological contrasts. Results indicate that children were less likely to disambiguate words differing by one phoneme than words differing by two or more phonemes, particularly when those one-phoneme differences were located at the beginning or end of the words (as in fim/vim). Overall, the findings suggest that children’s pragmatic assumptions about two contrasting words depend not only on if words differ, but also on how they differ.

This study investigated whether Korean children follow the acquisition pattern predicted by the Aspect Hypothesis (Shirai & Andersen, 1995), and the relationship between caretakers’ and children’s speech. Accordingly, we analyzed a Korean corpus (Ryu-Corpus) on the CHILDES database (MacWhinney, 2000), which comprised longitudinal video-recorded interactions of three Korean children and their caregivers. Results indicate that the children used the past marker -ess principally with telic verbs, consistent with the Aspect Hypothesis. Each child’s usage closely reflects the caretaker’s frequency, yielding a high correlation (τb = 0.79). However, the acquisition of the imperfective marker -ko iss did not show a predicted association with activity verbs, contrary to the Aspect Hypothesis. Furthermore, caretakers’ input did not correlate with the children’s utterances of the imperfective marker (τb = 0.40). We argue that multiple factors such as input frequency, language-specific organization of aspectual semantics, and individual differences should be considered to explain tense-aspect acquisition.

The aim of the present study was to investigate the acquisition of ditransitive structures beyond production. We conducted an elicitation task (production) and a picture-sentence matching task measuring accuracy and response times (comprehension). We examined German five-to seven-year-old typically developing children and an adult control group. Our data showed quasi-perfect performance in comprehension in adults and in those children who had already mastered ditransitives productively. However, children who had not yet mastered the production of ditransitives showed comprehension abilities preceding production abilities. Unlike adults, in the comprehension task children did not react explicitly before the end of the auditory stimulus.

A growing body of research suggests that individual variation in young children’s word comprehension (indexed by response times and accuracy) is structured and meaningful. In this paper, we assess how children’s word comprehension correlates with three factors: socio-economic status (indexed by maternal education), lingual status (based on language exposure), and age. We present results from 91 2- to 3-year-old children using a paired forced-choice task built on a child-friendly touch screen. Effects associated with maternal education and exposure to the tested language (French) were small, and they were greater for accuracy than response times. This pattern of results is compatible with an interpretation whereby the greatest effects of these two variables are on cumulative knowledge (vocabulary size) rather than on processing. Effects for age were larger and affected both accuracy and response times. Finally, response time variation did not mediate the effects of socio-economic status on accuracy or vice versa.

Young children with Down syndrome (DS) have language delays beginning early in life. Book reading with parents provides a context for capitalizing on language learning opportunities. This study evaluated the quantity and quality of language input among mothers and fathers of young children with DS during book reading interactions and investigated associations with child language. Findings revealed that mothers were more talkative and used more descriptive language, whereas fathers spent more time reading the book text. Moreover, maternal and paternal input were correlated with different measures of child language, suggesting that mothers and fathers may use divergent approaches to support language development.