To better understand the developmental trajectory of children's pragmatic development, studies that examine more than one type of implicature as well as associated linguistic and cognitive factors are required. We investigated three- to five-year-old English-speaking children's (N = 71) performance in ad hoc quantity, scalar quantity and relevance implicatures, as well as word learning by exclusion inferences, using a sentence-to-picture-matching story-based task. Children's pragmatic abilities improved with age, with word learning by exclusion acquired first, followed by relevance and ad hoc quantity implicatures, and finally scalar quantity implicatures. In an exploratory analysis (with a subset of the data N = 58), we found that structural language knowledge was a predictor of pragmatic performance (but no evidence for an association with socioeconomic status or Theory of Mind, controlling for structural language). We discuss reasons why this developmental pattern emerges with reference to linguistic and extra-linguistic properties of these inferences.

Multi-accent environments offer rich but inconsistent language input, as words are produced differently across accents. The current study examined, in two experiments, whether multi-accent variability affects infants’ ability to learn words and whether toddlers’ prior experience with accents modulates learning. In Experiment 1, two-and-a-half-year-old Norwegian toddlers were exposed, in their kindergarten, twice per day for one week, to a child-friendly audiovisual tablet-based e-book containing four novel pseudowords. Half of the toddlers heard the story in three Norwegian accents, whereas the other half heard it in one Norwegian accent. The results revealed no differences between conditions, suggesting that multi-accent variability did not hinder toddlers’ word learning. In experiment 2, two-and-a-half-year-old Norwegian toddlers were exposed, in their homes, for one week, to the e-book featuring three Norwegian accents. The results revealed overall better learning in toddlers raised in bi-dialectal households, as compared to mono-dialectal peers – suggesting that accent exposure benefits learning in multi-accent environments.

Since there are no systematic pauses delimiting words in speech, the problem of word segmentation is formidable even for monolingual infants. We use computational modeling to assess whether word segmentation is substantially harder in a bilingual than a monolingual setting. Seven algorithms representing different cognitive approaches to segmentation are applied to transcriptions of naturalistic input to young children, carefully processed to generate perfectly matched monolingual and bilingual corpora. We vary the overlap in phonology and lexicon experienced by modeling exposure to languages that are more similar (Catalan and Spanish) or more different (English and Spanish). We find that the greatest variation in performance is due to different segmentation algorithms and the second greatest to language, with bilingualism having effects that are smaller than both algorithm and language effects. Implications of these computational results for experimental and modeling approaches to language acquisition are discussed.

This study examines the effects of input quality on early phonological acquisition by investigating whether interadult variation in specific phonetic properties in the input is reflected in the production of their children. We analysed the English coda stop release patterns in the spontaneous speech of fourteen mothers and compared them with the spontaneous production of their preschool children. The analysis revealed a very strong positive input–production relationship; mothers who released coda stops to a lesser degree also had children who tended to not release their stops, and the same was true for mothers who released their stops to a higher degree. The findings suggest that young children are sensitive to acoustic properties that are subphonemic, and these properties are also reflected in their production, showing the importance of considering input quality when investigating child production.

Despite the fact that in most communities interaction occurs between the child and multiple speakers, most previous research on input to children focused on input from mothers. We annotated recordings of Sesotho-learning toddlers living in non-industrial Lesotho in South Africa, and French-learning toddlers living in urban regions in France. We examined who produced the input (mothers, other children, adults), how much input was child directed, and whether and how it varied across speakers. As expected, mothers contributed most of the input in the French recordings. However, in the Sesotho recordings, input from other children was more common than input from mothers or other adults. Child-directed speech from all speakers in both cultural groups showed similar qualitative modifications. Our findings suggest that input from other children is prevalent and has similar features as child-directed from adults described in previous work, inviting cross-cultural research into the effects of input from other children.

Previous research on the effects of word-level factors on lexical acquisition has shown that frequency and concreteness are most important. Here, we investigate CDI data from 1,030 Dutch children, collected with the short form of the Dutch CDI, to address (i) how word-level factors predict lexical acquisition, once child-level factors are controlled, (ii) whether effects of these word-level factors vary with word class and age, and (iii) whether any interactions with age are due to differences in receptive vocabulary. Mixed-effects regressions yielded effects of frequency and concreteness, but not of word class and phonological factors (e.g., word length, neighborhood density). The effect of frequency was stronger for nouns than predicates. The effects of frequency and concreteness decreased with age, and were not explained by differences in vocabulary knowledge. These findings extend earlier results to Dutch, and indicate that effects of age are not due to increases in vocabulary knowledge.

Children's remarkable ability to generalize beyond the input and the resulting overregularizations/ irregularizations provide a platform for a discussion of whether morphology learning uses analogy-based, rule-based, or statistical learning procedures. The present study, testing 115 children (aged 3 to 10) on an elicited production task, investigated the acquisition of the irregular distribution in the Turkish causative. Results showed that in early acquisition, to pin down the four causative suffixes, children engaged in comparisons between analogous exemplars. Thereafter to tackle the irregularity in two of the suffixes, children entertained competing hypotheses that yielded overregularizations and irregularizations. Overregularizations were instances of abstraction across the input based on type frequency; irregularizations were attempts to default to erroneous micro-generalizations. Negative correlation between errors and verb frequency suggested that recovery from errors was sensitive to token frequency. The overgeneralize-then-recover pattern that emerged in the acquisition of causative supported an integrated account of the roles of analogy, abstraction, and frequency in morphology learning.

Turkish-speaking dyzygotic twins (n = 21) and singletons (n = 23) were tested through a standard articulation test to observe whether their consonant articulations were related to their vocabulary sizes, recorded through CDI forms, at age 3;0. Twins were observed to lag behind their singleton peers and performed below the norm level in their production. Vocabulary size failed to predict twins’ articulation scores although it predicted the scores of the singleton group. The results suggested that articulation was not related to vocabulary size in twins. Exposure to sibling language was discussed as an alternative risk factor.

The current study investigates Spanish children's variation between the standard and non-standard forms for second person singular preterit –s (caiste ~ caístes). All second person singular preterit forms were extracted from the spontaneous speech of 78 children in Spain and analyzed for the effects of age, language contact setting, and lexical frequency. Results show that children in contact with Galician and Catalan produce more non-standard than children in non-contact areas like Madrid. Meanwhile, low-frequency verbs (e.g., pillaste) are more likely to occur with the non-standard –s than high-frequency verbs (e.g., fuiste). However, age is not a significant predictor of children's 2sg preterit production. These preliminary findings demonstrate that Spanish children do have the non-standard -s in their speech, and that their 2sg preterit forms are significantly conditioned by language contact and lexical frequency.

Children learn words in ambiguous situations, where multiple objects can potentially be referents for a new word. Yet, researchers debate whether children maintain a single word-object hypothesis – and revise it if falsified by later information – or whether children establish a network of word-object associations whose relative strengths are modulated with experience. To address this issue, we presented 4- to 12-year-old children with sets of mutual exclusivity (fast-mapping) trials: offering them with obvious initial hypotheses (that the novel object is the referent for the novel word). We observe that children aged six years and above, despite showing a novelty bias and retaining this novel word – novel object association, also formed an association between the novel word and the name-known object, thereby suggesting that older children attend to more than one word-object association, in a manner similar to associative learning. We discuss our findings in the context of competing theoretical accounts related to word learning.

This longitudinal study investigated the development of oral narrative skills in monolingual Swedish-speaking children (N = 17). The MAIN Cat/Dog stories were administered at four timepoints between age 4 and 9. Different narrative aspects were found to develop differently. In story comprehension, the children performed high already at T1 (4;4) and were at ceiling at T2 (5;10), whereas story structure developed significantly until T4 (9;4). Narrative length and syntactic complexity reached a plateau at T3 (7;4). Referent introduction was not mastered until T4. The results suggest that general conclusions regarding the development of narrative skills depend on the specific aspects studied.

This research addressed the question of whether children understand proper names differently from descriptions. We examined how children extend these two types of expressions from an initial object (a truck) owned by the experimenter to two identical objects created by transforming the initial object, both owned by the experimenter. Adults and 5/6-year-olds extended a name (“Tommy”) to only one post-transformation object, but extended a description (“my truck”) to both objects. Adults and 7-year-olds (but not 5/6-year-olds) also extended a description modeled as a name (“called My Truck”) to only one object. Like adults, children understand that proper names identify unique individuals, but that descriptions identify properties.