This study investigated how speaker certainty (a rational cue) and speaker benevolence (an emotional cue) influence children's willingness to learn words in a selective learning paradigm. In two experiments four- to six-year-olds learnt novel labels from two speakers and, after a week, their memory for these labels was reassessed. Results…

Children categorize native-accented speakers as local and non-native-accented speakers as foreign, suggesting they use accent (i.e., phonological proficiency) to determine social group membership. However, it is unclear if accent is the strongest--AND ONLY--group marker children use to determine social group membership, or whether other aspects of…

In languages with evidential marking, utterances consist of an informational content and a specification of the mode of access to that information. In this first longitudinal study investigating the acquisition of the Turkish evidential marker "-mIs" in naturalistic child-caregiver interactions, we examined six children between 8 and 36…

Valid indigenous language assessments are needed to further our understanding of how children learn language around the world. We assessed the psychometric properties and performance of two caregiver-report measures of Wolof language skill (language milestones achieved and vocabulary knowledge) for 500 children (ages 0;4 to 2;6) living in rural…

Children tend to regularize their productions when exposed to artificial languages, an advantageous response to unpredictable variation. But generalizations in natural languages are typically conditioned by factors that children ultimately learn. In two experiments, adult and six-year-old learners witnessed two novel classifiers, probabilistically…

Vocabulary input frequency influences age of acquisition, and is also an essential control for investigating the influence of other factors. We propose a new method of frequency estimation, self-report. 918 Danish-speaking parents of 12-36-month-old children estimated their frequency of use of 725 words. Self-report was substantially correlated…

Children's ability to refer is underpinned by their developing cognitive skills. Using a production task (n = 57), we examined pre-articulatory visual fixations to contrast objects (e.g., to a large apple when the target was a small one) to investigate how visual scanning drives informativeness across development. Eye-movements reveal that…

Finnish is a language with simple syllable structure but rich morphology. It was investigated whether syllables or morphemes are preferred processing units in early reading. To this end, Finnish first- and second-grade children read sentences with embedded inflected target words while their eye-movements were registered. The target words were…

Studies examining productive syntax have used varying elicitation methods and have tended to focus on either young children or adolescents/adults, so we lack an account of syntactic development throughout middle childhood. We describe here the results of an analysis of clause complexity in narratives produced by 354 speakers aged from four years…

This study compared the temporal measurements of stop consonants in 29 three- to six-year-old Mandarin-speaking children and 12 Mandarin-speaking adults. Each participant produced 18 Mandarin disyllabic words which contained six stop consonants /p, p?, t, t?, k, k?/ each followed by three vowels /a, i, u/ at the word-initial position in the first…

During the first two years of life, infants concurrently refine native-language speech categories and word learning skills. However, in the Switch Task, 14-month-olds do not detect minimal contrasts in a novel object--word pairing (Stager & Werker, 1997). We investigate whether presenting infants with acoustically salient contrasts (liquids)…

This longitudinal study assessed three acoustic components of maternal infant-directed speech (IDS) -- pitch, affect, and vowel hyperarticulation -- in relation to infants' age and their expressive vocabulary size. These three individual components were measured in IDS addressed to infants at 7, 9, 11, 15, and 19 months (N = 18). All three…

This study tested the claim of input-based accounts of language acquisition that children's inflectional errors reflect competition between different forms of the same verb in memory. In order to distinguish this claim from the claim that inflectional errors reflect the use of a morphosyntactic default, we focused on the Japanese verb system,…

To determine whether the developing semantic lexicon varies with culture, we examined the animal and food naming of children from three communities distinguished by language, cultural heritage, and population density. The children were fve- and seven-year-olds from Australia (n = 197), Taiwan (n = 456), and the US (n = 172). Naming patterns…

We explored whether supported (SJE) or coordinated joint engagement (CJE) between mothers recruited from the community and their 24-month-old children who were slow-to-talk at 18 months old were associated with child language scores at ages 24, 36, and 48 months (n = 197). We further explored whether SJE or CJE modifed the concurrent positive…