In the first year of life, infants' speech perception becomes attuned to the sounds of their native language. This process of early phonetic learning has traditionally been framed as phonetic category acquisition. However, recent studies have hypothesized that the attunement may instead reflect a perceptual space learning process that does not…

The first stage of combinatorial speech is better described as variable than uniform. Talk of variants obscures two different aspects of language (knowledge and use) and two different aspects of language development -- acquisition of the grammar (competence) and deployment of the grammar in speaking and listening (performance). Null subjects and…

Emerging audio technologies over the last decade have provided a new, unprecedented window into the everyday lives of infants and young children. These new approaches will allow us to begin to address longstanding questions about the nature of language experiences across languages, communities and situations and the role of these experiences in…

Poverty of the stimulus has been at the heart of ferocious and tear-filled debates at the nexus of psychology, linguistics, and philosophy for decades. This review is intended as a guide for readers without a formal linguistics or philosophy background, focusing on what poverty of the stimulus is and how it's been interpreted, which is…

This paper provides the first evidence of maternal speech--motherese--in Wichi, an indigenous language with a complex morphology spoken in the Gran Chaco region of Argentina. The corpus consists of 22 hours of video recordings from the daily life of three children, starting from their one-morpheme utterance period (MLU = 1) to the onset of…

This dissertation studies the acquisition of Mandarin relative clauses (RCs), including the distributional pattern of different RC types in adult child-directed speech (study 1) and four-year-old Mandarin-speaking children's comprehension of different RC types (study 2). An RC is a subordinate clause that modifies a noun and is embedded within a…

Through two elicited production experiments we investigated how preschool Italian-speaking children access the left periphery of the clause with respect to topics in Clitic Left Dislocation (ClLD) structures. Since the discourse conditions of the experiments are felicitous for the production of passives as well, we also investigated children's…

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…

This study investigates a strategy based on predictability of consecutive sub-lexical units in learning to segment a continuous speech stream into lexical units using computational modeling and simulations. Lexical segmentation is one of the early challenges during language acquisition, and it has been studied extensively through psycholinguistic…

Teachers and parents intuitively judge the 'level' of the child and the 'level' of the text and try to match them; they know that overestimation or underestimation of either will be met with restlessness or boredom. In this way, they have an empirical understanding of Vygotsky's ZPD--the zone of proximal development he envisioned as measuring the…

The words in children's language learning environments are strongly predictive of cognitive development and school achievement. But how do we measure language environments and do so at the scale of the many words that children hear day in, day out? The quantity and quality of words in a child's input are typically measured in terms of total amount…

The 'root infinitive' phenomenon in child speech is known from major languages such as Dutch. In this case study, a child acquiring the Papuan language Nungon in a remote village setting in Papua New Guinea uses two different non-finite verb forms as predicates of main clauses ('root' contexts) between ages 2;3 and 3;3. The first root non-finite…

Age of acquisition (AoA) refers to the age at which people learn a particular item and the AoA effect refers to the phenomenon that early-acquired items are processed more quickly and accurately than those acquired later. Over several decades, the AoA effect has been investigated using neuroscientific, behavioral, corpus and computational…

We examined case-marking variation in heritage Polish, Russian, and Ukrainian. Comparing heritage to homeland Polish and Ukrainian speakers, we found only a few types and a few tokens of systematic distinction between heritage and homeland varieties. A total of 6,291 instances of nouns and pronouns were extracted from transcribed conversations…

Models of language acquisition are constrained by the information that learners can extract from their input. Experiment 1 investigated whether 3-month-old infants are able to encode a repeated, unsegmented sequence of five syllables. Event-related-potentials showed that infants reacted to a change of the initial or the final syllable, but not to…