Children with language disorders have particular difficulty with verbs, but when this difficulty emerges is unknown. We examined syntactic (transitive, intransitive, ditransitive) and semantic (manner, result) features of two-year-olds’ verb vocabularies, contrasting late talkers and typically developing children to look for early differences in verb vocabulary. We conducted a retrospective analysis of parent-reported expressive vocabulary from the Language Development Survey (N = 564, N(LT) = 62) (Rescorla, 1989). Verbs were coded for the presence or absence of each syntactic and semantic feature. Binomial mixed-effects regressions revealed the effect of feature on children's knowledge and whether feature interacted with group classification. Our results revealed mostly similarities between late talkers and typically developing children. All children's vocabularies showed a bias against verbs that occur in ditransitive frames. One feature showed a difference between groups: late talkers showed a bias against manner verbs that typically developing children did not.

This study explores whether children can learn a structural processing bias relevant to pronoun interpretation from brief training. Over three days, 42 five-year-olds were exposed to narratives exhibiting a first-mentioned tendency. Two characters were introduced, and the first-mentioned was later described engaging in a solo activity. In our primary condition of interest, the Gesture Training condition, the solo-activity sentence contained an ambiguous pronoun, but co-speech gesture clarified the referent. There were two comparison conditions. In the Gender Training condition the characters were different genders, thereby avoiding ambiguity. In the Name Training condition, the first-mentioned name was simply repeated. Ambiguous pronoun interpretation was tested pre- and post-training. Children in the Gesture condition were significantly more likely to interpret ambiguous pronouns as the first-mentioned character after training. Results from the comparison conditions were ambiguous: there was a small but non-significant effect of training, but also no significant differences between conditions.

Gesture plays an important role in early language development, as how parents respond to their children's gestures may help to facilitate language acquisition. Less is known about whether parental responses facilitate language learning later in childhood and whether responses vary depending on children's language ability. This study explored parental responses to extending gestures in a sample of school-aged children (aged six to eight years) with developmental language disorder, low-language and educational concerns, and typically developing children. Overall there were no group differences in the types of responses parents provided to extending gestures. Parents predominantly responded with positive feedback but also displayed moderate proportions of verbal translations and clarification requests. Within the DLD group, the proportion of parent translations was negatively associated with language ability. Our finding suggests that parent responses serve to enhance communication and engage children in tasks, but there is limited evidence that they support new language learning at this age.

This study examined the relations between receptive language development and other developmental domains of preschoolers from low-income families, through an inter-cultural perspective involving the United States and Turkey. A total of 471 children and their caregivers participated in Turkey, while 287 participated in the United States. Children's development was assessed using the Ages and Stages Questionnaire for both samples. Different versions of the Peabody Picture Vocabulary Test were used for Turkish and US samples, to measure receptive language development. Results revealed similar patterns, with some differences, between the two countries. Receptive language predicted only communication and personal–social scales in the Turkish sample, while the US children's receptive language skills were associated with communication, problem solving, personal–social, and fine and gross motor development scales. These results were discussed in the context of each country, and the comparative conclusions contribute to the extant literature by illustrating the importance of language for three domains.

Monolingual children identify referents uniquely in gesture before they do so with words, and parents translate these gestures into words. Children benefit from these translations, acquiring the words that their parents translated earlier than the ones that are not translated. Are bilingual children as likely as monolingual children to identify referents uniquely in gesture; and do parental translations have the same positive impact on the vocabulary development of bilingual children? Our results showed that the bilingual children – dominant in English or in Spanish – were as likely as monolingual children to identify referents uniquely in gesture. More importantly, the unique gestures, when translated into words by the parents, were as likely to enter bilingual and monolingual children's speech – independent of language dominance. Our results suggest that parental response to child gesture plays as crucial of a role in the vocabulary development of bilingual children as it does in monolingual children.

Previous research suggests that English monolingual children and adults can use speech disfluencies (e.g., uh) to predict that a speaker will name a novel object. To understand the origins of this ability, we tested 48 32-month-old children (monolingual English, monolingual French, bilingual English–French; Study 1) and 16 adults (bilingual English–French; Study 2). Our design leveraged the distinct realizations of English (uh) versus French (euh) disfluencies. In a preferential-looking paradigm, participants saw familiar–novel object pairs (e.g., doll–rel), labeled in either Fluent (“Look at the doll/rel!”), Disfluent Language-consistent (“Look at thee uh doll/rel!”), or Disfluent Language-inconsistent (“Look at thee euh doll/rel!”) sentences. All participants looked more at the novel object when hearing disfluencies, irrespective of their phonetic realization. These results suggest that listeners from different language backgrounds harness disfluencies to comprehend day-to-day speech, possibly by attending to their lengthening as a signal of speaker uncertainty. Stimuli and data are available at <https://osf.io/qn6px/>.

One of the most popular and widely used parent report instruments for assessing early language acquisition is the MacArthur-Bates Communicative Development Inventories (MB-CDI). This study compares normative data of the Italian Words and Sentences complete form (WS-CF) and short form (WS-SF). The samples included 752 children for the WS-CF and 816 children for the WS-SF designed for children aged 18–36 months. The concordance between WS-SF and WS-CF is analyzed in a subgroup of 65 children. The results revealed strong correlations between WS-CF and WS-SF in both lexical and grammar skills as well as strong relationship between lexical and grammar skills. There was a high percentage agreement (97%) between the two forms for scores below the 10th percentile, suggesting that the two forms may be used interchangeably in order to describe vocabulary and grammatical development.

Phonological characteristics and frequencies of stems and allomorphs have been explored as possible factors causing differences in production accuracies between allomorphic forms. However, previous findings are not consistent and the relative contributions of these factors are unclear. This study investigated target and erroneous productions of the Dutch diminutive, which has five allomorphs with varying type frequencies and of which the selection depends on the phonological characteristics of the stems. Typically developing children (N = 115, 5;1–10;3) were tested on their production of real and nonce diminutives. Linear mixed effects modelling was used to analyse the data taking nonverbal IQ into account. Type frequencies of the allomorphs and differences in phonological characteristics of the stems were found to be related to differences in production accuracies between the allomorphs. However, phonological characteristics of the stems appeared to have a bigger impact, mainly due to the phonological complexity of these characteristics.

We examined if and when English-learning 17-month-olds would accommodate Japanese forms as labels for novel objects. In Experiment 1, infants (n = 22) who were habituated to Japanese word–object pairs looked longer at switched test pairs than familiar test pairs, suggesting that they had mapped Japanese word forms to objects. In Experiments 2 (n = 44) and 3 (n = 22), infants were presented with a spoken passage prior to habituation to assess whether experience with a different language would shift their perception of Japanese word forms. Here, infants did not demonstrate learning of Japanese word–object pairs. These findings offer insight into the flexibility of the developing perceptual system. That is, when there is no evidence to the contrary, 17-month-olds will accommodate forms that vary from their typical input but will efficiently constrain their perception when cued to the fact that they are not listening to their native language.

Previous studies have demonstrated an effect of early vocal production on infants’ speech processing and later vocabulary. This study focuses on the relationship between vocal production and new word learning. Thirty monolingual Italian-learning infants were recorded at about 11 months, to establish the extent of their consonant production. In parallel, the infants were trained on novel word–object pairs, two consisting of early learned consonants (ELC), two consisting of late learned consonants (LLC). Word learning was assessed through Preferential Looking. The results suggest that vocal production supports word learning: Only children with higher, consistent consonant production attended more to the trained ELC images.