Human languages, signed and spoken, can be characterized by the structural patterns they use to associate communicative "forms" with "meanings." One such pattern is paradigmatic morphology, where complex words are built from the systematic use "and re-use" of sub-lexical units. Here, we provide evidence of emergent…

Languages exhibit variation at all linguistic levels, from phonology, to the lexicon, to syntax. Importantly, that variation tends to be (at least partially) conditioned on some aspect of the social or linguistic context. When variation is unconditioned, language learners regularize it -- removing some or all variants, or conditioning variant use…

English-speaking children use plural morphology from around the age of 2, yet often omit the syllabic plural allomorph /-[schwa]z/ until age 5 (e.g., "bus(es)"). It is not clear if this protracted acquisition is due to articulatory difficulties, low input frequency, or fricative-final words (e.g., "bus," "nose") being…

The present study analyses 3- to 6-year-old children's dialect-standard repertoires in an Austrian-Bavarian sociolinguistic setting and investigates how far individual repertoires can be explained by input and sociodemographic factors. Adults' linguistic repertoires in the area typically comprise a certain spectrum on the dialect-standard…

Specific features of adult linguistic input may play a larger, or smaller role, at different child ages, across different language outcomes, in different cohorts. This prospective, longitudinal study explored associations between the quantity and quality (i.e. diversity and responsiveness) of maternal linguistic input and child language. This…

Research in language development has only recently begun to focus on the inherent variability of language. Previous studies have explored at what age children begin to produce variable linguistic forms and how these forms progress through development. While children produce adult-like variation early on, some variable forms take longer to acquire…

We examined French-learning toddlers' sensitivity to Subject-Verb agreement with conjoined subjects. In French, a conjoined NP triggers plural agreement even when made up of individual singular NPs. Processing of this infrequent structure in the input (see Corpus Analyses) requires going beyond surface patterns of non-adjacent dependencies to…

The present study investigated the effect of classroom-based syntactic training on children's abilities to produce passive sentences. Thirty-three monolingual English children (mean age 5;2), were involved in passive-voice training based on storytelling sessions within a priming design. The training was delivered in a classroom setting, with two…

Researchers disagree as to the importance for infant language learning of isolated words, which occur relatively rarely in input speech. Brent and Siskind (2001) showed that the first words infants "produce" are words their mothers used most frequently in isolation. Here we investigate the long-term effects of presentation mode on…

Bilingual children are often exposed to non-native speech through their parents. Yet, little is known about the relation between bilingual preschoolers' speech production and their speech input. The present study investigated the production of voice onset time (VOT) by Dutch-German bilingual preschoolers and their sequential bilingual mothers. The…

Previous research has shown that an increased second language (L2) vocabulary size leads to better attunement to the cues required to distinguish L2 contrastive phones. This has been the central tenet of the vocabulary-tuning model (vocab) on the basis of evidence by Japanese learners of English in Australia. We aim to test the validity of the…

Languages differ in how they encode causal events, placing greater or lesser emphasis on the agent or patient of the action. Little is known about how these preferences emerge and the relative influence of cognitive biases and language-specific input at different stages in development. In these studies, we investigated the emergence of sentence…

Infants are thought to be sensitive to frequency in the input as a cue for phonological development. However, linguistic biases such as phonological markedness have been argued to play a role too. Since frequency and markedness are correlated, the two assertions could be different interpretations of data that confound frequency and markedness. In…

By their second birthday, children have begun using grammatical cues to decipher the meaning of newly encountered words. By 3 years of age, there is evidence that children are more reliant on grammatical than social cues to decipher verb meaning (Nappa, Wessel, McEldoon, Gleitman, & Trueswell, 2009). Here, we investigate children's reliance on…

While previous sociolinguistic research has demonstrated that children faithfully acquire probabilistic input constrained by sociolinguistic and linguistic factors (e.g., gender and socioeconomic status), research suggests children regularize inconsistent input-probabilistic input that is not sociolinguistically constrained (e.g., Hudson Kam &…