This study investigated how infants deal with cross-talker variability in the perception of native lexical tones, paying specific attention to developmental changes and the role of task demands. Using the habituation-based visual fixation procedures, we tested Cantonese-learning infants of different age groups on their ability to discriminate Cantonese Tone 1 (high level) and Tone 3 (mid level) produced by either multiple talkers or a single talker. Results demonstrated that the 12-month-old and 24-month-old groups showed reliable discrimination across talkers, whereas the 18-month-old group did not (Experiment 1), despite their ability to discriminate the same contrast when the talker was held constant (Experiment 2). In a task that included a novel object as a referent to the sound, the 18-month-olds discriminated the contrast across talkers from Tone 1 to Tone 3 (Experiment 3). These results revealed a U-shaped developmental path and perceptual asymmetry in native lexical tone discrimination across talkers.

Compounds (e.g., jellybeans) and list forms (e.g., jelly, beans) can be distinguished by the presence or absence of boundaries, marked by durational and pitch cues. Studies have shown that 5-year-olds learning English have acquired both cues for distinguishing compounds and lists. However, it is not clear how and when this ability is acquired by children speaking tonal languages, such as Mandarin. This study examined whether Mandarin-speaking preschoolers can use durational and pitch cues to distinguish compounds and lists and whether their productions are adult-like. Thirty-one 4-year-olds, 34 5-year-olds, 29 6-year-olds, and 43 adults participated in an elicited production experiment. Results showed that similar to English-speaking preschoolers, Mandarin-speaking preschoolers can use durational cues to mark boundaries, triggering appropriate pitch changes for distinguishing compounds and lists, though these were not fully adult-like, even in the oldest age group.

Time is frequently structured in terms of motion as moving-time (e.g., “summer is coming”), moving-ego (e.g., “we approach winter”), or sequence-as-position (e.g., “winter follows autumn”) across the world’s languages, including Chinese – a language that shows greater variability in its expression of such metaphors. Using a metaphor explanation and a metaphor comprehension task, we tested 60 children learning Chinese, equally divided into ages 3–4, 5–6, 7–8. Children’s performance improved with age, marking ages 7–8 as the period with significant gains in both comprehension and explanation of metaphors – a later mastery compared to children learning English shown in earlier work. Metaphor type also affected children’s performance, but only for the explanation and not the comprehension of metaphors. Overall, our findings highlight that the structure of spatial metaphors for time in Chinese influences the timing but not the trajectory of children’s development in learning spatial metaphors for time.

Regional accent biases in 27 Essex five-year-olds are investigated. This study is the first to analyse implicit language attitudes by measuring children’s neural activity (event-related potentials) while they take part in an Implicit Association Test. Both measures find a preference towards the prestigious accent, Standard Southern British English (SSBE), which is associated with cleverness (CLEVER). A late positive potential in the brain data for the association of the familiar, low-prestige Essex accent with CLEVER suggests the children also have a positive association with their home accent. The association between the less familiar, low-prestige Yorkshire accent and either CLEVER or NOT-CLEVER depends on the measure. Differences in the results are found relating to the children’s accent exposure; those with a more heterogenous group of caretakers show more positive bias towards all three accents overall. Consequences for modelling the development of language attitudes are discussed.

Co-speech gestures accompany or replace speech in communication. Studies investigating how autistic children understand them are scarce and inconsistent and often focus on decontextualized, iconic gestures. This study compared 73 three- to twelve-year-old autistic children with 73 neurotypical peers matched on age, non-verbal IQ, and morphosyntax. Specifically, we examined (1) their ability to understand deictic (i.e., pointing), iconic (e.g., gesturing ball), and conventional (e.g., gesturing hello) speechless video-taped gestures following verbal information in a narrative and (2) the impact of linguistic (e.g., vocabulary, morphosyntax) and cognitive factors (i.e., working memory) on their performance, to infer on the underlying mechanisms involved. Autistic children displayed overall good performance in gesture comprehension, although a small but significant difference advantage was observed in neurotypical children. Findings suggest that combining speech and gesture sequentially may be relatively spared in autism and might represent a way to alleviate the demand for simultaneous cross-modal processing.

The prolonged developmental window of irony understanding opens up the question of which socio-cognitive repertoire underlies this pragmatic capacity. In the present study, we investigated the relationship between epistemic vigilance and irony understanding in 5/6- and 6/7-year-old children using a picture selection task. We assessed children’s vigilance towards unreliable informants and manipulated the reliability of the irony target. Our findings confirm that irony comprehension is a late-emerging skill and highlight the need to differentiate its full-fledged understanding from mere sensitivity to contextual mismatches. While irony understanding was not affected by our reliability manipulation, our findings revealed that more vigilant children were better at irony understanding than less vigilant ones. This provides the first empirical evidence that epistemic vigilance is a good predictor of irony performance and lays the ground for future research on the intricate relationship between these two capacities.

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.

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.

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.

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.

Expanded vowel or tone space in IDS has traditionally been interpreted as evidence of enhanced acoustic contrasts. However, emerging evidence from various languages shows that the within-category acoustic variability of vowels and tones also increases in IDS, offsetting the benefit of space expansion and leading to non-enhanced, or reduced acoustic contrasts. This study re-analysed a corpus of Mandarin IDS and ADS, showing that, relative to ADS, vowels and tones in IDS display greater variability, resulting in non-enhanced contrasts. Thus, given increased variability, expanded vowel or tonal space in IDS may not necessarily equate to enhanced acoustic contrasts.

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.

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.

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.

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.

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.

Despite the importance of cognitive development for vocabulary acquisition, limited attention has been given to the impacts of cognitive factors on this phenomenon from a longitudinal perspective. This study evaluates the longitudinal development of such factors (i.e. metacognitive knowledge, working memory, and non-verbal intelligence) and L2 vocabulary knowledge growth in 210 young second language learners enrolled in a bilingual programme in China. Results supported individual differences in the initial level and the growth rate of learners’ cognitive development and vocabulary knowledge growth: a higher starting level of cognitive development correlated with a higher level of vocabulary knowledge and a faster rate of vocabulary knowledge growth. Findings revealed particularly significant predictive role of metacognitive knowledge on vocabulary knowledge, followed by non-verbal intelligence and working memory. Relevant implications were discussed based on the findings.

Numerous developmental findings suggest that infants and toddlers engage predictive processing during language comprehension. However, a significant limitation of this research is that associative (bottom-up) and predictive (top-down) explanations are not readily differentiated. Following adult studies that varied predictiveness relative to semantic-relatedness to differentiate associative vs. predictive processes, the present study used eye-tracking to begin to disentangle the contributions of bottom-up and top-down mechanisms to infants’ real-time language processing. Replicating prior results, infants (14-19 months old) use successive semantically-related words across sentences (e.g., eat, yum, mouth) to predict upcoming nouns (e.g., cookie). However, we also provide evidence that using successive semantically-related words to predict is distinct from the bottom-up activation of the word itself. In a second experiment, we investigate the potential effects of repetition on the findings. This work is the first to reveal that infant language comprehension is affected by both associative and predictive processes.