This study examined the acquisition of numeral classifiers in 120 monolingual Japanese children. Previous research has argued that the complex semantic system underlying classifiers is late acquired. Thus, we set out to determine the age at which Japanese children are able to extend the semantic properties of classifiers to novel items/situations. Participants completed a comprehension task with a mouse-tracking extension and a production task with nonce and familiar items. While the comprehension results showed ceiling effects on familiar and nonce items, age significantly modulated a difference in accuracy between familiar and nonce items in the production task. The findings suggest that the acquisition of the underlying semantic system is acquired much earlier than previously argued. Previously attested issues with Japanese classifier production in young(er) children are more likely to reflect accessing difficulties than indexing the underlying grammatical competence of the classifier system.

We compare two frameworks for the segmentation of words in child-directed speech, PHOCUS and MULTICUE. PHOCUS is driven by lexical recognition, whereas MULTICUE combines sub-lexical properties to make boundary decisions, representing differing views of speech processing. We replicate these frameworks, perform novel benchmarking and confirm that both achieve competitive results. We develop a new framework for segmentation, the DYnamic Programming MULTIple-cue framework (DYMULTI), which combines the strengths of PHOCUS and MULTICUE by considering both sub-lexical and lexical cues when making boundary decisions. DYMULTI achieves state-of-the-art results and outperforms PHOCUS and MULTICUE on 15 of 26 languages in a cross-lingual experiment. As a model built on psycholinguistic principles, this validates DYMULTI as a robust model for speech segmentation and a contribution to the understanding of language acquisition.

Six-month-olds infer object size based on pitch: they map high-pitched vowels onto smaller objects and low-pitched vowels onto larger objects (Peña et al., 2011). The ‘sound symbolism bootstrapping hypothesis’ (Imai & Kita, 2014) proposes that this may support understanding of word-meaning correspondences; by drawing on iconic pairings between linguistic cues and corresponding referents (e.g., higher pitch for smaller objects), infants develop understanding of word-referent associations. Here we analyse mother-child interactions, testing whether sound-symbolic pitch-size correspondences occur in infant-directed speech. 40 dyads engaged in (semi-)naturalistic interaction around picture books containing images of toys of varying sizes. We compare mothers’ pitch when referring to small versus large toys, analysing i) actual size (bigger vs. smaller toys); ii) relative toy size congruence (i.e., congruent vs. incongruent with real-world expectation); and iii) transparency of the test paradigm as regards its focus on size contrastiveness (non-transparent, moderately transparent, highly transparent) to observe the nuances of size sound symbolism in infant-directed speech.

During the recent pandemic, it became necessary to adapt lab-based studies to online experiments. To investigate the impact of online testing on the quality of data, we focus on three paradigms widely used in infant research: a word recognition task using the Intermodal Preferential Looking Paradigm, a word learning task using the Switch task, and a language assessment tool (WinG) where children identify a target word amongst a set of picture cards. Our results for synchronous and asynchronous studies provide support for the robustness of online testing. In Experiment 1, robust word recognition was found in 24-month-old toddlers. In Experiment 2, 17-month-old infants consistently learned a new word. Finally, Experiment 3 demonstrated that 19- to 26-month-old children performed well on a language assessment test administered online. Overall, effect sizes or language scores were found to be higher than in lab-based studies. These experiments point to promising possibilities for reaching out to families around the world.

Mean Length of Utterance (MLU) has been widely used to measure children’s early language development in a variety of languages. This study investigates the utility of MLU to measure language development in four agglutinative and morphologically complex Southern Bantu languages. Using a variant of MLU, MLU3, based on the three longest sentences children produced, we analysed the utterances of 448 toddlers (16-32 months) collected using the MacArthur-Bates Communicative Development Inventory, a parent-report tool. MLU3, measured in words (MLU3-w) and morphemes (MLU3-m), significantly correlated with age and other indices of language growth (e.g., grammar and vocabulary). MLU3 measures also accounted for significant variance in language development particular morphosyntactic development. Our results suggest that MLU3-m is a more sensitive measure than MLU3-w. We conclude that MLU measured in morphemes provides a useful addition to other indices of language development in these kinds of morphologically complex languages.

Children exhibit preferences for familiar accents early in life. However, they frequently have more difficulty distinguishing between first language (L1) accents than second language (L2) accents in categorization tasks. Few studies have addressed children’s perception of accent strength, or the relation between accent strength and objective measures of pronunciation distance. To address these gaps, 6- and 12-year-olds and adults ranked talkers’ perceived distance from the local accent (i.e., Midland American English). Rankings were compared with objective distance measures. Acoustic and phonetic distance measures were significant predictors of ladder rankings, but there was no evidence that children and adults significantly differed in their sensitivity to accent strength. Levenshtein Distance, a phonetic distance metric, was the strongest predictor of perceptual rankings for both children and adults. As a percept, accent strength has critical implications for social judgments, which determine real world social outcomes for talkers with non-local accents.

Many studies have explored children’s acquisition of temporal adverbs. However, the extent to which children’s early temporal language has discursive instead of solely temporal meanings has been largely ignored. We report two corpus-based studies that investigated temporal adverbs in Finnish child-parent interaction between the children’s ages of 1;7 and 4;11. Study 1 shows that the two corpus children used temporal adverbs to construe both temporal and discursive meanings from their early adverb production and that the children’s usage syntactically broadly reflected the input received. Study 2 shows that the discursive uses of adverbs appeared to be learned from contextually anchored caregiver constructions that convey discourse functions like urging and reassuring, and that the usage is related to the children’s and caregivers’ interactional roles. Our study adds to the literature on the acquisition of temporal adverbs by demonstrating that these items are learned also with additional discursive meanings in family interaction.

A wide variety of language skills has been shown to be compromised in children from low socioeconomic status (SES). However, few studies have investigated the effect of SES on language development in infants. The aim of this study is two-fold: to investigate when the first SES-effects on language can be observed and to explore the effects of three variables often claimed to be linked to SES – gestational duration, stress and parent-child interaction – on language development. Parents/caregivers of 539 Dutch-acquiring infants aged 8-13 months from mid to high SES backgrounds completed a questionnaire including the LENA Developmental Snapshot (Gilkerson et al., 2017a) and the Brigance Parent-Child Interaction Scale (Glascoe & Brigance, 2002). No association was found between SES and language development. However, the results suggest that corrected age and parent-child interaction positively influence language development at this early age.

Combining adjective meaning with the modified noun is particularly challenging for children under three years. Previous research suggests that in processing noun-adjective phrases children may over-rely on noun information, delaying or omitting adjective interpretation. However, the question of whether this difficulty is modulated by semantic differences among (subsective) adjectives is underinvestigated.

A visual-world experiment explores how Italian-learning children (N=38, 2;4–5;3) process noun-adjective phrases and whether their processing strategies adapt based on the adjective class. Our investigation substantiates the proficient integration of noun and adjective semantics by children. Nevertheless, alligning with previous research, a notable asymmetry is evident in the interpretation of nouns and adjectives, the latter being integrated more slowly. Remarkably, by testing toddlers across a wide age range, we observe a developmental trajectory in processing, supporting a continuity approach to children’s development. Moreover, we reveal that children exhibit sensitivity to the distinct interpretations associated with each subsective adjective.

Young Romance speakers can structure their sentences by dislocating multiple constituents to the left periphery, resulting in non-canonical word orders. Production data, however, show that this ordering is rigid: only SOV sequences are attested, an observation reminiscent of Superiority. The first goal of the paper is to replicate this observation in comprehension; the second is to derive the Subject-over-Object pattern in terms of Intervention, with the additional assumption that only nested chains count as interveners. Three experiments are reported here. Experiment 1 and Experiment 2 show that SOVs interpretations are systematically favored over OSV and that not only Number features, but also a [+Topic] feature help to overcome intervention. Experiment 3 addresses a potential confound related to the clitic. These results integrate existing intervention-based accounts, traditionally built on relatives, providing not only new evidence coming from matrix clauses, but also investigating the role of information-structure features.

This study mapped the trajectory of developing derivational morphological knowledge in Hebrew monolingual and Russian–Hebrew bilingual children. We investigated 2nd and 4th graders, using a two-by-two structure along the dimensions of modality (comprehension, production) and type of word (real-word, pseudo-word). Performance in the morphological analogies comprehension tasks improved with grade, and monolingual and bilingual children performed equally well. A different pattern was evident in production tasks. In real-word production, monolingual children were more accurate than bilingual children, but this group difference narrowed with age. In pseudo-word production, monolingual children used more morphological elements than bilingual children, and there was also a tendency towards group differences narrowing with age. Detailed error analyses across all tasks revealed that monolingual children recruited more morphological elements than bilingual children. We present implications for assessment of morphological knowledge, and suggest that morphological intervention is a promising avenue for promoting bilingual children’s success.

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.

This scoping review aimed to investigate the communication strategies utilized by children who acquire a minority language (L1) and subsequently learn a community language (L2) during what is commonly referred to as the “silent period.” Electronic database searches were conducted using keywords such as “silent period” and “bilingual children,” resulting in the inclusion of 40 studies in the review. The findings revealed that emergent bilingual children utilize various communication strategies, including nonverbal communication, private speech, and their L1, to communicate within classroom environments. The findings shed light on the adaptability of emergent bilingual children during early stage of L2 acquisition. Furthermore, our review provides information about the classroom contexts such as teacher support and peer interactions where children develop their L2 skills. From a clinical perspective, recognizing these strategies and classroom contexts could significantly enhance the screening process for emergent bilingual children.

This study aims to investigate the practice patterns used by Portuguese speech-language pathologists (SLPs) with preschool-age children with pragmatic impairment and to identify the actual need(s) perceived by SLPs in this field. A total of 351 SLPs responded. The results reveal that 81.5 per cent of the respondents (n=286) reported working or had previously worked with preschool-age children with pragmatic impairment arising from autism spectrum disorder, developmental language disorder, or both. Considering the clinical practice, similarities and differences were found, many of which are due not to the inherent characteristics of each disorder but to the scarcity of research in clinical pragmatics. These results are also reflected in the needs perceived by SLPs and the degree of confidence with which they work with these children. Implications for clinical practice and directions for future research are discussed.

Late talkers (LTs) exhibit delayed vocabulary development, which might stem from a lack of a typical word learning strategy to generalise object labels by shape, called the ‘shape bias’. We investigated whether LTs can acquire a shape bias and whether this accelerates vocabulary learning. Fourteen LTs were randomly allocated to either a shape training group (Mage = 2.76 years, 6 males), which was taught that objects similar in shape have the same name, or a control group (Mage = 2.61 years, 4 males), which was taught real words without any focus on object shape. After seven training sessions, children in the shape training group generalised trained labels by shape (d = 1.28), but not unfamiliar labels. Children in the control group extended all labels randomly. Training did not affect expressive vocabulary.

Quantifier spreading (Q-spreading), children’s incorrect falsification of a universally-quantified sentence based on an ‘extra-object’ picture, may persist beyond childhood, and children adhere to Q-spreading without changing responses throughout testing. We examined the error patterns across wider age groups (aged 4-79) with a picture-sentence verification eye-tracking task. We also examined whether prosodic emphasis affects their comprehension and processing of universally-quantified sentences. Whereas adults’ comprehension was ceiling, children/adolescents (aged 4-17) showed various comprehension patterns, splitting into: ‘Adult-like responders’ (consistently adult-like), ‘Q-spreaders’ (consistently showing Q-spreading), and ‘Switchers’ (shifted from Q-spreading to adult-like). While adults rarely looked at the extra-object, ‘Q-spreaders’ showed frequent looks throughout testing, and both ‘Switchers’ and ‘Adult-like responders’ exhibited reduced looks to the extra-object, suggesting that avoidance and correction of Q-spreading requires inhibition of the visual attention to the extra-object. The effect of prosodic emphasis on eye movement emerged later for children/adolescents than adults.

As a result of the Covid-19 pandemic, public life in many countries ground to a halt in early 2020. The aims of this study were (i) to uncover the language practices of multilingual families during the pandemic, in general and especially regarding homeschooling; and (ii) to determine to what extent the changes in circumstance caused by the pandemic impacted children’s language use and proficiency, and family well-being. Parents from 587 families completed an online survey for 1051 children. Data were analysed using ordinal logistic regression. Our results showed that for most children, there were no changes in language use, proficiency or well-being. When there were changes, these were more likely for (families with) preschool children. Using the heritage language for homeschooling (some or all of the time) did not have a negative impact on Dutch language proficiency, but it did have a positive impact on the heritage language proficiency.

We examined the neurophysiological underpinnings of lexical-tone and vowel-quality perception in learners of a non-tonal language. We tested 25 6- and 25 9-month-old German-learning infants, as well as 24 German adults and expected developmental differences for the two linguistic properties, as they are both carried by vowels, but have a different status in German. In adults, both lexical-tone and vowel-quality contrasts elicited mismatch negativities, with a stronger response to the vowel-quality contrast. Six-month-olds showed positive mismatch responses for lexical-tone and vowel-quality contrasts, with an emerging negative mismatch response for vowel-quality only. The negative mismatch responses became more pronounced for the vowel-quality contrast at 9 months, while the lexical-tone contrast elicited mainly positive mismatch responses. Our data reveal differential developmental changes in the processing of vowel properties that differ in their lexical relevance in the ambient language.

Mental State Talk (MST) is utterances describing invisible mental aspects. The first aim of this study was to investigate the characteristics of Parental MST and Child MST and their concurrent association in a Swedish population, and the second aim was to relate these MST measures to the children’s general language abilities. Seventy-seven dyads of parents and their 25-month-old toddlers participated. MST was assessed by videotaping the dyads during free-play sessions in a laboratory and general language abilities were based on parental reports. Forty-nine toddlers did not produce MST, while all parents used MST. Child MST was positively associated with vocabulary and grammar. Parental MST was not associated with Child MST nor the children’s general language abilities. In exploratory analyses, Parental MST referred to another than the child was positively correlated with vocabulary and grammar. Further studies are needed to confirm these findings and continue studying MST in different linguistic contexts.

We investigated the dynamics of communicative initiation in infant−caregiver interactions across ages and language abilities. Analyses of 228 Language ENvironment Analysis (LENA) recordings from 141 Korean adult−child dyads (60 girls; aged 7−30 months) replicated the initiator effect reported in North American populations. This effect, demonstrated by longer utterances, more frequent speech, and shorter response times in self-initiated interactions for both children and adults, suggests potential cross-cultural consistency in this conversational dynamic and remained consistent across ages in most conversational measures. A focused analysis of 13–14 month-olds (N = 40) and their K-CDI scores revealed that the initiator effect in segment duration and number persisted across most vocabulary percentiles. Additionally, nuanced findings indicated that caregivers increased their input frequency and adjusted segment duration in adult-initiated conversations in tandem with children’s higher receptive abilities. The robustness of the initiator role across cultures, ages, and vocabulary abilities points to a fundamental aspect of human communication.