Speakers display considerable variability in language use and representations: they may have different pronunciations of the same word, different intended meanings for the same phrases, and different sets of syntactic constraints in their internalized grammars. Comprehenders adapt to such variability by constantly updating their expectations for…

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…

Language is one of the hallmarks of intelligence, demanding explanation in a theory of human cognition. However, language presents unique practical challenges for quantitative empirical research, making many linguistic theories difficult to test at naturalistic scales. Artificial neural network language models (LMs) provide a new tool for studying…

In this article, I argue that first language (L1), second language (L2) and third language (L3) acquisition are fundamentally the same process, based on learning by parsing. Both child and adult learners are sensitive to fine linguistic distinctions, and language development takes place in small steps. While the bulk of the article focuses on…

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…

Computational models have shown that purely statistical knowledge about words' linguistic contexts is sufficient to learn many properties of words, including syntactic and semantic category. For example, models can infer that "postman" and "mailman" are semantically similar because they have quantitatively similar patterns of…

Traditionally, acquisition of syntactic knowledge and the development of sentence comprehension behaviors have been treated as separate disciplines. This article reviews a growing body of work on the development of incremental sentence comprehension mechanisms and discusses how a better understanding of the developing parser can shed light on two…

This article investigates near-native grammars at the syntax--discourse interface by examining the second language (L2) acquisition of two different domains of object movement in Dutch, which exhibit syntax-discourse or syntax-semantics level properties. English and German near-native speakers of Dutch, where German but not English allows the same…

Generative approaches to language have long recognized the natural link between theories of knowledge representation and theories of knowledge acquisition. The basic idea is that the knowledge representations provided by Universal Grammar enable children to acquire language as reliably as they do because these representations highlight the…

We compare the predictions of two different accounts of first language acquisition by investigating the relative contributions of abstract syntax and input frequency to the elicited production of main and embedded questions by 36 monolingual English-speaking toddlers aged 3;00 to 5;11. In particular, we investigate whether children's accuracy…

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…

Two studies investigated syntactic productivity in three-year-old Mandarin speakers' use of verbs in the SVO and S"ba"OV constructions. In Study 1, children were taught novel verbs in one construction and assessed for their production in the other construction. Children produced verbs taught in the "ba" constructions in…

The "syntactic bootstrapping" hypothesis proposes that syntactic structure provides children with cues for learning the meaning of novel words. In this article, we address the question of how children might start acquiring some aspects of syntax before they possess a sizeable lexicon. The study presents two models of early syntax…

Young English-speaking children often omit auxiliary verbs from their speech, producing utterances such as "baby crying" alongside the more adult-like "baby is crying." Studies have found that children's proficiency with auxiliary BE is correlated with frequency statistics in the input, leading some researchers to argue that…

Situated within second language (L2) research about the acquisition of morphosyntax, this study investigated English L2 speakers' detection and primed production of a novel construction with morphological and structural features. We report on two experiments with Thai (n = 69) and Farsi (n = 70) English L2 speakers, respectively, carried out an…