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…

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…

Children acquire argument structure through distributional evidence, but how does this interacts with event semantics and existing verb knowledge? The current study compares verb learning in adult speakers of Japanese (where lexical causatives span wider semantic categories) and English (where alternation is more restricted). In the Fully…

Beginning with the classic work of Shepard, Hovland, & Jenkins (1961), Type II visual patterns (e.g., exemplars are large white squares OR small black triangles) have held a special place in investigations of human learning. Recent research on Type II "linguistic" patterns has shown that they are relatively frequent across languages…

For adults, "no" and "not" change the truth-value of sentences they compose with. To investigate children's emerging understanding of these words, an experimenter hid a ball in a bucket or a truck, then gave an affirmative or negative clue (Experiment 1: "It's not in the bucket"; Experiment 2: "Is it in the…

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 &…

The phenomenon of regularization -- learners imposing systematicity on inconsistent variation in language input -- is complex. Studies show that children are more likely to regularize than adults, but adults will also regularize under certain circumstances. Exactly why we see the pattern of behaviour that we do is not well understood, however.…

Many English-speaking children use plural nominal forms in spontaneous speech before the age of two, and display some understanding of plural inflection in production tasks. However, results from an intermodal preferential study suggested a lack of "comprehension" of nominal plural morphology at 24 months of age (Kouider, Halberda, Wood,…

Syntactic bootstrapping facilitates children's initial learning of verb meanings based on syntactic information. A challenging case is the argument-drop languages, where the number of argument NPs is not a reliable cue for distinguishing between transitive and intransitive verbs. Despite this fact, the availability of syntactic bootstrapping in…

Across a diverse range of languages, children proceed through similar stages in their production of causal language: their initial verbs lack internal causal structure, followed by a period during which they produce causative overgeneralizations, indicating knowledge of a productive causative rule. We asked in this study whether a child not…

A noun can be potentially ambiguous as to whether it is a head on its own, or is a modifier of a Noun + Noun compound waiting for its head. This study investigates whether young children can exploit the prosodic information on a modifier constituent preceding the head to facilitate resolution of such ambiguity in Japanese. Evidence from English…

According to the Integration of Multiple Patterns hypothesis (IMP; Treiman & Kessler, 2014), the spelling difficulty of a word is affected by the number of cues converging on the correct answer. We tested this hypothesis in children's regular past tense formation in Dutch. Past tenses are formed by adding either-"de"…

Three experiments investigated the acquisition of English epistemic modal verbs (e.g., "may", "have to"). Semantically, these verbs encode possibility or necessity with respect to available evidence. Pragmatically, the use of weak epistemic modals often gives rise to scalar conversational inferences (e.g., "The toy may be…

To acquire the meanings of verbs, toddlers make use of the surrounding linguistic information. For example, 2-year-olds successfully acquire novel transitive verbs that appear in semantically rich frames containing content nouns ("The boy is gonna pilk a balloon"), but they have difficulty with pronominal frames ("He is gonna pilk…

The present experiments investigated the flexibility of statistical word segmentation. There is ample evidence that infants can use statistical cues (e.g., syllable transitional probabilities) to segment fluent speech. However, it is unclear how effectively infants track these patterns in unfamiliar phonological systems. We examined whether…