The English modal system is complex, exhibiting many-to-one, and one-to-many, form-function mappings. Usage-based approaches emphasise the role of the input in acquisition but rarely address the impact of form-function mappings on acquisition. To test whether consistent form-function mappings facilitate acquisition, we analysed two dense mother-child corpora at age 3 and 4. We examined the influence on acquisition of input features including form-function mapping frequency and the number of functions a modal signifies, using innovative methodological controls for other aspects of the input (e.g., form frequency) and child characteristics (e.g., age as a proxy for socio-cognitive development). The children were more likely to produce the frequent modals and form-function mappings of their input but modals with fewer functions in caregiver speech did not promote acquisition of these forms. Our findings support usage-based approaches to language acquisition and demonstrate the importance of applying appropriate controls when investigating relationships between input and development.

This study reports on the feasibility of using the Test of Complex Syntax- Electronic (TECS-E), as a self-directed app, to measure sentence comprehension in children aged 4 to 5 ½ years old; how testing apps might be adapted for effective independent use; and agreement levels between face-to-face supported computerized and independent computerized testing with this cohort. A pilot phase was completed with 4 to 4;06-year-old children, to determine the appropriate functional app features required to facilitate independent test completion. Following the integration of identified features, children completed the app independently or with adult support (4–4;05 (n = 22) 4;06–4;11 months (n = 55) and 5 to 5;05 (n = 113)) and test re-test reliability was examined. Independent test completion posed problems for children under 5 years but for those over 5, TECS-E is a reliable method to assess children’s understanding of complex sentences, when used independently.

Young children today are exposed to masks on a regular basis. However, there is limited empirical evidence on how masks may affect word learning. The study explored the effect of masks on infants’ abilities to fast-map and generalize new words. Seventy-two Chinese infants (43 males, Mage = 18.26 months) were taught two novel word-object pairs by a speaker with or without a mask. They then heard the words and had to visually identify the correct objects and also generalize words to a different speaker and objects from the same category. Eye-tracking results indicate that infants looked longer at the target regardless of whether a speaker wore a mask. They also looked longer at the speaker’s eyes than at the mouth only when words were taught through a mask. Thus, fast-mapping and generalization occur in both masked and not masked conditions as infants can flexibly access different visual cues during word-learning.

This study investigated the developmental pattern of early lexical production and composition in Mandarin-speaking children. Forty Mandarin-speaking children and their parents participated in this one-and-a-half-year longitudinal study, and naturalistic samples of parent-to-child speech in toy play were collected when the children were 1;8, 2;2, and 3;0. The results showed that children’s lexical production increased significantly between ages 1;8 and 3;0. The proportion of closed-class words increased significantly with age, whereas the proportion of common nouns showed the inverse pattern, indicating the role of grammatical words increased as the children grew. Furthermore, nouns and verbs were predominant in Mandarin-speaking children between ages 1;8 and 3;0, and Mandarin-speaking children used more verbs than nouns at 2;2 and 3;0 in the toy play context. The longitudinal study clarifies early lexical development in Mandarin-speaking children, which provides a valuable contrast for different language systems.

Previous research has shown language-specific features play a guiding role in how children develop expression of events with speech and gestures. This study adopts a multimodal approach and examines Mandarin Chinese, a language that features context use and verb serializations. Forty children (four-to-seven years old) and ten adults were asked to describe fourteen video stimuli depicting different types of causal events involving location/state changes. Participants’ speech was segmented into clauses and co-occurring gestures were analyzed in relation to causation. The results show that the older the children, the greater the use of contextual clauses which contribute meaning to event descriptions. It is not until the age of six that children used adult-like structures – namely, using single gestures representing causing actions and aligning them with verb serializations in single clauses. We discuss the implications of these findings for the guiding role of language specificity in multimodal language development.

This study is a validation of the LENA system for the Italian language. In Study 1, to test LENA’s accuracy, seventy-two 10-minute samples extracted from daylong LENA recordings were manually transcribed for 12 children longitudinally observed at 1;0 and 2;0. We found strong correlations between LENA and human estimates in the number of Adult Word Count (AWC) and Child Vocalisations Count (CVC) and a weak correlation between LENA and human estimates in Conversational Turns Count (CTC). In Study 2, to test the concurrent validity, direct and indirect language measures were considered on a sample of 54 recordings (19 children). Correlational analyses showed that LENA’s CVC and CTC were significantly related to the children’s vocal production, a parent report measure of prelexical vocalizations and the vocal reactivity scores. These results confirm that the automatic analyses performed by the LENA device are reliable and powerful for studying language development in Italian-speaking infants.

Pointing plays a significant role in communication and language development. However, in spoken languages pointing has been viewed as a non-verbal gesture, whereas in sign languages, pointing is regarded to represent a linguistic unit of language. This study compared the use of pointing between seven bilingual hearing children of deaf parents (Kids of Deaf Adults [KODAs]) interacting with their deaf parents and five hearing children interacting with their hearing parents. Data were collected in 6-month intervals from the age of 1;0 to 3;0. Pointing frequency among the deaf parents and KODAs was significantly higher than among the hearing parents and their children. In signing dyads pointing frequency remained stable, whereas in spoken dyads it decreased during the follow-up. These findings suggested that pointing is a fundamental element of parent-child interaction, regardless of the language, but is guided by the modality, gestural and linguistic features of the language in question.

Previous research on infant-directed speech (IDS) and its role in infants’ language development has largely focused on mothers, with fathers being investigated scarcely. Here we examine the acoustics of IDS as compared to adult-directed speech (ADS) in Norwegian mothers and fathers to 8-month-old infants, and whether these relate to direct (eye-tracking) and indirect (parental report) measures of infants’ word comprehension. Forty-five parent-infant dyads participated in the study. Parents (24 mothers, 21 fathers) were recorded reading a picture book to their infant (IDS), and to an experimenter (ADS), ensuring identical linguistic context across speakers and registers. Results showed that both mothers’ and fathers’ IDS had exaggerated prosody, expanded vowel spaces, as well as more variable and less distinct vowels. We found no evidence that acoustic features of parents’ speech were associated with infants’ word comprehension. Potential reasons for the lack of such a relationship are discussed.

The current study investigated whether vocabulary relates to phonetic categorization at neural level in early childhood. Electoencephalogram (EEG) responses were collected from 53 Dutch 20-month-old children in a passive oddball paradigm, in which they were presented with two nonwords “giep” [ɣip] and “gip” [ɣɪp] that were contrasted solely by the vowel. In the multiple-speaker condition, both nonwords were produced by twelve different speakers; while, in the single-speaker condition, one single token of each word was used as stimuli. Infant positive mismatch responses (p-MMR) were elicited in both conditions without significant amplitude differences. When the infants were median split based on vocabulary level, the large and small vocabulary groups showed comparable p-MMR amplitudes yet different scalp distribution in both conditions. These results suggest successful phonetic categorization of native similar sounding vowels at 20 months, and a close relationship between speech categorization and vocabulary development.

This study examines correlations between the prosody of infant-directed speech (IDS) and children’s vocabulary size. We collected longitudinal speech data and vocabulary information from Dutch mother-child dyads with children aged 18 (N = 49) and 24 (N = 27) months old. We took speech context into consideration and distinguished between prosody when mothers introduce familiar vs. unfamiliar words to their children. The results show that IDS mean pitch predicts children’s vocabulary growth between 18 and 24 months. In addition, the degree of prosodic modification when mothers introduce unfamiliar words to their children correlates with children’s vocabulary growth during this period. These findings suggest that the prosody of IDS, especially in word-learning contexts, may serve linguistic purposes.

Based on the linguistic analysis of game explanations and retellings, the paper’s goal is to investigate the relation of preschool children’s situated discourse competence and iconic gestures in different communicative genres, focussing on reinforcing and supplementary speech-gesture-combinations. To this end, a method was developed to evaluate discourse competence as a context-sensitive and interactively embedded phenomenon. The so-called GLOBE-model was adapted to assess discourse competence in relation to interactive scaffolding. The findings show clear links between the children’s competence and their parents’ scaffolding. We suggest this to be evidence of a fine-tuned interactive support system. The results also indicate strong relations between higher discourse competence and increased frequency of iconic gestures. This applies in particular to reinforcing gestures. The results are interpreted as a confirmation that the speech-gesture system undergoes systematic changes during early childhood, and that gesturing becomes more iconic – and thus more communicative – when discourse competence is growing.

The ability to process plural marking of nouns is acquired early: at a very young age, children are able to understand if a noun represents one item or more than one. However, little is known about how the segmental characteristics of plural marking are used in this process. Using eye-tracking, we aim at understanding how five to twelve-year old children use the phonetic, phonological, and morphological information available to process noun plural marking in German (i.e., a very complex system) compared to adults. We expected differences with stem vowels, stem-final consonants or different suffixes, alone or in combination, reflecting different processing of their segmental information. Our results show that for plural processing: 1) a suffix is the most helpful cue, an umlaut the least helpful, and voicing does not play a role; 2) one cue can be sufficient and 3) school-age children have not reached adult-like processing of plural marking.

Infant-directed speech (IDS) produced in laboratory settings contains acoustic cues, such as pauses, pitch changes, and vowel-lengthening that could facilitate breaking speech into smaller units, such as syntactically well-formed utterances, and the noun- and verb-phrases within them. It is unclear whether these cues are present in speech produced in more natural contexts outside the lab. We captured LENA recordings of caregiver speech to 12-month-old infants in daylong interactions (N = 49) to address this question. We found that the final positions of syntactically well-formed utterances contained greater vowel lengthening and pitch changes, and were followed by longer pauses, relative to non-final positions. However, we found no evidence that these cues were present at utterance-internal phrase boundaries. Results suggest that acoustic cues marking the boundaries of well-formed utterances are salient in everyday speech to infants and highlight the importance of characterizing IDS in a large sample of naturally-produced speech to infants.

The study investigates the acquisition of Hebrew zero and pronominal subjects in the context of first and second person. We provide distributional evidence relative to verb tense, number, person, and conversational utterance type, in a peer-talk corpus (2;0-8;0 years). Findings show that acquisition starts early on, that verb inflectional morphology is crucial for the development of pronominal subjects, and that communicative contexts affect subject realization. Zero and pronominal subjects are not evenly distributed relative to the study variables, and cannot be treated as an alternation. A cluster analysis shows that each realization is linked to a distinguishable usage pattern, corresponding with particular discursive and communicative functions. These are defined as three Discourse Profile Constructions: (A) “calling for action” by 1st.Pl.Fut zero subjects (3;0 year olds); (B) “commenting on the interlocutor’s actions” by 2nd.Sg.Past zero subjects (ages 4;0-6;0); and (C) “planning one’s own actions” by 1st.Sg.Fut pronominal subjects (7;0-8;0 year olds).

Demonstrative words are one of the most important ways of establishing reference in conversation. This work describes Spanish-speaking children’s demonstrative production between ages 2 to 10 using data from the CHILDES corpora. Results indicate that children feature all demonstratives in their lexicon – however, the distal term is scarce throughout development. Moreover, patterns of demonstrative use are not adult-like at age 10. We compare adult and child data to conclude that children’s development of demonstrative production is largely protracted. Adult use of the distal demonstrative is higher than in young children, although both older children and adults use the medial term ese more than any other demonstratives. In contrast, younger children use proximals relatively more frequently than older children and adults. Suggestions for future research and theoretical implications for the Spanish demonstrative system are discussed.

In Lebanese Arabic, lexical subjects may occur before or after verbs, but only before non-verbal predicates. Analysis of spontaneous language samples from 19 two-year-old children shows that postverbal (VS) and preverbal (SV) subjects emerge simultaneously. The youngest children displayed no VS-SV difference in frequency. A slight preference for SV is observed in older children. No preference for SV subjects was found in the speech of the mothers of the younger or older children. Lexical subjects systematically appeared before non-verbal predicates. We interpret these results as evidence for early knowledge of syntactic movement, consistent with Wexler’s (1998) Very Early Parameter Setting.

Previous studies have shown that caregivers’ sensitive, responsive interactions with young children can boost language development. We explored the association between caregivers’ sensitivity and the vocabulary development of their 8-to-36-month-olds during COVID-19 when family routines were unexpectedly disrupted. Measuring caregivers’ sensitivity from home interaction videos at three timepoints, we found that children who experienced more-sensitive concurrent interactions had higher receptive and expressive vocabularies (N=100). Children whose caregivers showed more-sensitive interactions at the beginning of the pandemic showed greater expressive vocabulary growth six (but not 12) months later (n=58). Significant associations with receptive vocabulary growth were not observed. Our findings highlight the importance of sensitivity at a time when other positive influences on language development were compromised.

We examined how noun frequency and the typicality of surrounding linguistic context contribute to children’s real-time comprehension. Monolingual English-learning toddlers viewed pairs of pictures while hearing sentences with typical or atypical sentence frames (Look at the… vs. Examine the…), followed by nouns that were higher- or lower-frequency labels for a referent (horse vs. pony). Toddlers showed no significant differences in comprehension of nouns in typical and atypical sentence frames. However, they were less accurate in recognizing lower-frequency nouns, particularly among toddlers with smaller vocabularies. We conclude that toddlers can recognize nouns in diverse sentence contexts, but their representations develop gradually.

Typically-developing bilingual children often score lower than monolingual peers of the same age on standardized measures; however, research has shown that when assessed in more natural discourse contexts, bilinguals can perform similar to age-matched monolinguals in some language subdomains. This study investigated complex syntax production in simultaneous French–English bilingual children and monolingual age-matched peers, using structured and spontaneous measures. Surprisingly, the bilinguals scored higher than the monolinguals on the structured task. There was no difference between groups on the spontaneous measure; however, predictors of complex syntax production differed by language groups and by tasks. Contrary to other language subdomains showing bilingual English development as protracted relative to monolingual peers, these results point to a relative strength of complex syntax acquisition among simultaneous bilingual children. Differences in exposure relative to monolingual children may be less pronounced in syntax, in part because bilinguals can benefit from syntactic knowledge in their other language.

Parental language input influences child language outcomes but may vary based on certain characteristics. This research examined how parental language differs during two contexts for toddlers at varying likelihood of autism based on their developmental skills. Parental language (quantity, quality, and pragmatic functions) was analyzed during dyadic play and mealtime interactions as a secondary data analysis of observational data from a study of toddlers at elevated and lower likelihood of autism. Child developmental skills and sensory processing were also assessed. Parents used more words per minute, directives, and verbs during play and more adjectives, descriptions, and questions during mealtime. Parental language differed based on child fine motor skills, receptive language, and levels of sensory hyporesponsiveness but not autism likelihood. Overall, this study found that parental language varies based on context and child developmental skills. Future research examining parental language should include pragmatic functions and context across developmental trajectories.