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.

From early on, infants show a preference for infant-directed speech (IDS) over adult-directed speech (ADS), and exposure to IDS has been correlated with language outcome measures such as vocabulary. The present multi-laboratory study explores this issue by investigating whether there is a link between early preference for IDS and later vocabulary size. Infants’ preference for IDS was tested as part of the ManyBabies 1 project, and follow-up CDI data were collected from a subsample of this dataset at 18 and 24 months. A total of 341 (18 months) and 327 (24 months) infants were tested across 21 laboratories. In neither preregistered analyses with North American and UK English, nor exploratory analyses with a larger sample did we find evidence for a relation between IDS preference and later vocabulary. We discuss implications of this finding in light of recent work suggesting that IDS preference measured in the laboratory has low test-retest reliability.

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.

To investigate how a high risk for infant neurological impairment affects the quality of infant verbal interactions, and in particular properties of infant-directed speech, spontaneous interactions between 14 mothers and their 4.5-month-old infants at high risk for neurological disorders (7 female) were recorded and acoustically compared with those of 14 dyads with typically developing infants (8 female). Mothers of at-risk infants had proportionally less voicing, and the proportion of voicing decreased with increasing severity of the infants’ long-term outcome. Follow-up analysis based on manual annotation of phonation style revealed breathy phonation as more common toward infants with more severe long-term outcomes (N=7; 44.7% of speech) than controls (N=14; 22.0%; p=0.005) or at-risk infants with typical or mildly abnormal long-term outcomes (N=7; 16.5%; p=0.002). The results indicate that maternal phonation style during early dyadic interactions is affected by the infant’s neurological condition.

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.

This study investigates Navajo verbs produced by four children, ages 4;07 to 11;02, during conversations with their caretakers. Analyses of 1600 verbs demonstrate that the bisyllabic verb form, consisting of a verb stem and a portion of the prefix string, is the most common pattern produced by the children. This indicates that Navajo-speaking children use meaningful units of verbal morphology that do not necessarily adhere to the linguistic boundaries normally ascribed to the Navajo verb complex. Further, the verbs are primarily intransitive and third-person singular constructions, which are minimally inflected. It is argued that these minimally-inflected verb forms are frequent not just because they are simpler, but also because they are highly productive as main verbs and are used to create phrasal verbs and nouns. These findings contribute to our general understanding of language development and to the growing body of research investigating children’s acquisition of endangered Indigenous languages.

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.

We report findings from a corpus-based investigation of three young children growing up in German-English bilingual environments (M = 3;0, Range = 2;3–3;11). Based on 2,146,179 single words and two-word combinations in naturalistic child speech (CS) and child-directed speech (CDS), we assessed the degree to which the frequency distribution of CDS predicted CS usage over time, and systematically identified CS that was over- or underrepresented in the corpus with respect to matched CDS baselines. Results showed that CDS explained 61% of the variance in CS single-word use and 19.3% of the variance in two-word combinations. Furthermore, the bilingual nature of the over or -underrepresented CS was partially attributable to factors beyond the corpus statistics, namely individual differences between children in their bilingual learning environment. In two out of the three children, overrepresented two-word combinations contained higher levels of syntactic slot redundancy than underrepresented CS. These results are discussed with respect to the role that redundancy plays in producing semiformulaic slot-and-frame patterns in CS.

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 study investigates the changes in the Spanish lexical and grammatical skills of 26 Spanish–English dual language learners during their first year of preschool. We also explore the impact of age, gender, and maternal cultural orientation on children’s language outcomes over time. The results show that, despite one year of English-only instruction, the children’s Spanish productions became more intelligible, lexically diverse, and grammatical between 3;7 and 4;7. However, Spanish productions were mostly limited to sentence fragments and contained errors in grammatical gender, verb morphology, object clitic pronouns, and prepositions. Girls had an advantage over boys, as attested by the higher lexical diversity, mean length of utterance, and grammaticality of their Spanish productions. Both maternal enculturation and acculturation predicted the grammaticality of children’s utterances, suggesting that mothers with high levels of orientation to both Latinx and American culture may be the most successful at promoting Spanish in the United States.

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.

English-speaking autistic children use the hesitation marker um less often than non-autistic children but use uh at a similar rate. It is unclear why this is the case. We employed a sample of Dutch-speaking children from the Preschool Brain Imaging and Behavior Project to examine hesitation markers in autistic and non-autistic preschoolers with the aim to 1) make a crosslinguistic comparison of hesitation marker usage and 2) examine hypotheses regarding the underlying linguistic mechanisms of hesitation markers: the symptom hypothesis and the signal hypothesis. We found initial group differences in all hesitation markers but these results were rendered insignificant after controlling for age, sex and nonverbal cognition. We found significant correlations between hesitation marker usage and expressive and receptive language, but not autism traits. Lastly, we show interesting cross-linguistic differences in hesitation marker usage between Dutch-speaking participants and previously described English-speaking participants, such as a preference for um over uh.