In this paper, we investigate the effect of neighbourhood density (ND) on vocabulary size in a computational model of vocabulary development. A word has a high ND if there are many words phonologically similar to it. High ND words are more easily learned by infants of all abilities (e.g. Storkel, 2009; Stokes, 2014). We present a neural network model that learns general phonotactic patterns in the exposure language, as well as specific word forms and, crucially, mappings between word meanings and word forms. The network is faster at learning frequent words, and words containing high-probability phoneme sequences, as human word learners are, but, independently of this, the network is also faster at learning words with high ND, and, when its capacity is reduced, it learns high ND words in preference to other words, similarly to late talkers. We analyze the model and propose a novel explanation of the ND effect, in which word meanings play an important role in generating word-specific biases on general phonological trajectories. This explanation leads to a new prediction about the origin of the ND effect in infants.

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/>.

The current study examined five- and seven-year-old Mandarin-speaking children's processing of lexical tones in relation to speech segments by varying onset and rime in an oddity task (onset±rime±). Results showed that children experienced more difficulty in lexical tone oddity judgment when rimes differed across monosyllables (e.g. onset+rime−) than when onsets differed (e.g. onset−rime+). This finding suggests that vowels interfere more than consonants in lexical tone processing. Seven-year-olds consistently outperformed five-year-olds, suggesting that the growth of metalinguistic awareness and literacy exposure may play a joint role in the development of lexical tone processing skills.

Attempts were made to elicit poems from 133 children between the ages of 2;3 and 6;11. Seventy-eight of the children produced 606 poems between them. Forty-five per cent of the poems contained the syntactic device of modified repetition: a substitution exercise where a grammatical frame is repeated and the substitution occurs in part of the grammatical frame. This was so despite the fact that modified repetition was not present in the examples that were used to elicit poems from the children. The frequency and types of modified repetition used by the children did not vary much with age. The question of whether children's use of modified repetition in their rhythmical poems has the function of helping them to practise grammatical forms, or whether it is simply one reflection of a general human tendency towards the use of pattern in language, is discussed.

Previous research has shown that in a minority–majority language context, the quantity of language input at home is more important for the development of the minority language than for the development of the majority language. In the current study, we examined whether the same holds true for the frequency of specific language activities at home. In a group of five- and six-year-old Frisian–Dutch bilingual children (n = 120), we investigated to what extent vocabulary and morphology knowledge were predicted by reading activities, watching TV, and story-telling activities in both languages. The results showed that reading in Frisian predicted both Frisian vocabulary and morphology, while reading in Dutch only predicted Dutch vocabulary. This shows that reading at home is most important for the development of the minority language. This especially holds true for the acquisition of Frisian morphology, a domain that is known to be vulnerable in language acquisition.

In relatively unstructured interviews, Maratha and Brahmin children in Maharashtra, India, are asked to identify and to speak about household members, relatives, friends, and neighbours. It is argued that characteristic features of the usages and definitions of so-called ‘kin’ terms of young children as compared to those of adults reflect not only an incomplete grasp of the adult system of kinship reference, but also a quite accurate understanding of the deictic system of address in which kinship per se plays at most a peripheral role. It is further argued that, following Silverstein and Levinson, pragmatic rules of use play a major role in this address system and that, pace Piaget and others, these rules are acquired by a form of observational learning which requires that children be able to take another's point of view.

The acquisition of verb inflections in Tamil, an agglutinating language, was investigated in three 2-year-old children. The findings revealed a high percentage use of verb inflections indicating tense, aspect, modality, person, number and gender by all three children. Explanations for this early, almost error-free acquisition are discussed in terms of the facilitating properties of agglutinating languages.

This paper represents a partial condensation of the results of a study covering 14 months in a Russian-speaking child's phonological development. The original investigation tested a theory of phonological acquisition formulated by Olmsted (1971), finding that – though modifications were necessary to accommodate certain aspects of the Russian data – Olmsted's hypotheses were, by and large, upheld. The present paper gives the evidence in support of the theory and offers in addition some detailed information on the Russian-speaking child's acquisition of specific phones over the months examined.

Children's differing learning trajectories cross-linguistically have been at the forefront of gender acquisition research, often with conflicting results and conclusions. As a result, the source of children's different learning behaviors in gender acquisition has been unclear. I argue that children's gender acquisition is driven by the search for productive patterns. First, I provide corpus studies where the predictions of a learning model (Yang, 2016) are formulated. Second, I report the results of an elicited production task on Icelandic-speaking children (N = 26, ages 2;6-6;3 years) and adults (N = 18) that puts these predictions to test. The results suggest that Icelandic-speaking children and adults draw a categorical distinction between productive and unproductive suffixes in Icelandic gender assignment. I discuss the implications of these findings for morphological learning beyond gender acquisition.

The attribution of function of various kinds to elements of child speech is discussed, and the question of the validity of the interpretations on which such attribution rests is explored with reference to Halliday's work on the development of meaning. Work in the philosophy of language is used to explore the kind of evidence needed for valid interpretation, and its systematic nature within a framework of the structure of linguistic behaviour. It is argued that theoretical clarity in this area would aid the study of both language use and language acquisition.

In lexical development, the specificity of phonological representations is important. The ability to build phonologically specific lexical representations predicts the number of words a child knows (vocabulary breadth), but it is not clear if it also fosters how well words are known (vocabulary depth). Sixty-six children were studied in kindergarten (age 5;7) and first grade (age 6;8). The predictive value of the ability to learn phonologically similar new words, phoneme discrimination ability, and phonological awareness on vocabulary breadth and depth were assessed using hierarchical regression. Word learning explained unique variance in kindergarten and first-grade vocabulary depth, over the other phonological factors. It did not explain unique variance in vocabulary breadth. Furthermore, even after controlling for kindergarten vocabulary breadth, kindergarten word learning still explained unique variance in first-grade vocabulary depth. Skill in learning phonologically similar words appears to predict knowledge children have about what words mean.

Some subordinating conjunctions reveal whether speakers believe the propositions the conjunctions connect and how speakers believe propositions are connected. Because and although express belief; if + indicative and unless uncertainty, and if + subjunctive, disbelief. Because, if + indicative and if + subjunctive express a positive entailment relation between clauses while although and unless express negative entailment. To validate this analysis a comprehension task was administered to 96 subjects divided among 9-, 11- and 19-year-olds. Nine-year-olds understood although and because while adults also comprehended unless and if + indicative. Generally the more positive beliefs the conjunction embodied, the easier its comprehension. The order of difficulty was because, although, if + indicative, unless, and if + subjunctive. Older subjects more often confused if + subjunctive with if + indicative. Understanding of the uncertainty conveyed by if + indicative and unless was linked to performance on a task of detecting uncertain outcomes.

Parental input is considered a key predictor of language achievement during the first years of life, yet relatively few studies have assessed its effects on longer-term outcomes. We assess the effects of parental quantity of speech, use of parentese (the acoustically exaggerated, clear, and higher-pitched speech), and turn-taking in infancy, on child language at 5 years. Using a longitudinal dataset of daylong LENA recordings collected with the same group of English-speaking infants (N=44) at 6, 10, 14, 18, 24 months and then again at 5 years, we demonstrate that parents’ consistent (defined as stable and high) use of parentese in infancy was a potent predictor of lexical diversity, mean length of utterance, and frequency of conversational turn-taking between children and adults at Kindergarten entry. Together, these findings highlight the potential importance of a high-quality language learning environment in infancy for success at the start of formal schooling.

This study investigated the longitudinal relationship between children’s domain-general cognitive constraints underlying phonological and sentence processing development in a big sample of typically developing children. 104 children were tested on non-linguistic processing speed, phonological skills (phonological short term memory, phonological knowledge, phonological working memory), and sentence processing abilities (sentence repetition and receptive grammar) in 1st grade (aged 6 to 6.5) and one year later. A cross-lagged structural equation model showed that non-linguistic processing speed was a concurrent predictor of phonological skills, and that phonology had a powerful effect on the child’s sentence processing abilities concurrently and longitudinally, providing clear evidence for the role of domain-general processes in the developmental pathway of language. These findings support a cascaded cognitive view of language development and pose important challenges for evaluation and intervention strategies in childhood.

The objective of this study was to examine the links between prosodic features of paternal Infant-Directed Speech (IDS) and child characteristics. Pitch variability measures were extracted from the speech samples of 50 fathers during unstructured play with their two-year-old children. Evidence for a link between child receptive language ability (measured by the Bayley Scales of Infant Development III) and fathers’ pitch variability was obtained from Multiple Hierarchical Regression. Findings support the hypothesis that fathers tailor their speech to their children. This is one of the few studies to examine the relationship between fathers’ IDS and child language ability.

Much research has focused on the expression of voluntary motion (Slobin, 2004; Talmy, 2000). The present study contributes to this body of research by comparing how children (three to ten years) and adults narrated short, animated cartoons in English and German (satellite-framed languages) vs. French (verb-framed). The cartoons showed agents displacing themselves in variable Manners along different Paths (Path saliency and variance were specifically manipulated in four item types). Results show an increase with age across languages in how much information participants expressed. However, at all ages, more motion information was encoded in English and German than in French. Furthermore, language-specific features impacted the content and its organization within utterances in discourse, showing more variation within and across Path types in French than in the satellite-framed languages, resulting in later achievement of adult-like descriptions in this language. The discussion highlights the joint impact of cognitive and typological features on language development.