Over recent decades much research has analyzed the relevance of 9- to 20-month-old infants' early imitation skills (object- and language-based imitation) for language development. Yet there have been few systematic comparisons of the joint relevance of these imitative behaviors later on in development. This correlational study investigated whether…

In two visual world experiments we disentangled the influence of order of mention (first vs. second mention), grammatical role (subject vs object), and semantic role (proto-agent vs proto-patient) on 7- to 10-year-olds' real-time interpretation of German pronouns. Children listened to "SVO" or "OVS" sentences containing active…

Speaking intelligibly is an important achievement in children's language development. How far do congenitally severe-to-profound hearing-impaired children who received a cochlear implant (CI) in the first two years of their life advance on the path to intelligibility in comparison to children with typical hearing (NH)? Spontaneous speech samples…

Large individual differences in language skills are well documented in monolingual children (e.g., Kidd, Donnelly & Christiansen, 2018). In bilinguals, the broad variation is even more pronounced. Interestingly, some bilingual children might be weak in their Heritage Language (HL, also labeled as Minority Language, Home Language, Community…

There is considerable controversy over the factors that shape infants' developing knowledge of grammar. Work with artificial languages suggests that infants' ability to track statistical regularities within the speech they hear could, in principle, support grammatical development. However, little work has tested whether infants' performance on…

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…

Children's early vocabulary shows sex differences -- with boys having smaller vocabularies than age-comparable girls -- a pattern that becomes evident in both singletons and twins. Twins also use fewer words than their singleton peers. However, we know relatively less about sex differences in early gesturing in singletons or twins, and also how…

Fourteen-month-old infants are unable to link minimal pair nonsense words with novel objects (Stager & Werker, 1997). Might an adult's productions in a word learning context support minimal pair word-object association in these infants? We recorded a mother interacting with her 24-month-old son, and with her 5-month-old son, producing nonsense…

Iconic words imitate their meanings. Previous work has demonstrated that iconic words are more common in infants' early speech, and in adults' child-directed speech (e.g., Perry et al., 2015; 2018). This is consistent with the proposal that iconicity provides a benefit to word learning. Here we explored iconicity in four diverse language…

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…

We select three word segmentation models with psycholinguistic foundations -- transitional probabilities, the diphone-based segmenter, and PUDDLE -- which track phoneme co-occurrence and positional frequencies in input strings, and in the case of PUDDLE build lexical and diphone inventories. The models are evaluated on caregiver utterances in 132…

Research on sources of individual difference in parental Infant-Directed Speech (IDS) is limited and there is a particular lack of research on fathers' compared to mothers' speech. This study examined the predictive relations between infant characteristics and variability in paternal lexical diversity (LD) in dyadic free play with two-year-olds (M…

Bilingual children are a more heterogenous group than their monolingual counterparts with respect to the sources of variation in their language learning environments, as well as the wide individual variation in their language abilities. Such heterogeneity in both individual difference factors and language abilities argues for the importance of an…

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…

This paper addresses how input variability in the adult phonological system is mastered in the output of young children in Akan, a Kwa language spoken in Ghana, involving variability between labio-palatalized consonants and front rounded vowels. The high-frequency variant involves a complex consonant which is expected to be mastered late, while…