In Krashen's theory of second-language acquisition he claims that there is distinction between language acquisition and language learning, a distinction which other second-language acquisition researchers have called "perhaps the most important conceptualization" in the field and which has made possible the most productive models of SLA.…

Language is subject to a variety of pressures. Recent work has documented that many aspects of language structure have properties that appear to be shaped by biases for the efficient communication of semantic meaning. Other work has investigated the role of social pressures, whereby linguistic variants can acquire positive or negative evaluation…

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…

The purpose of this state-of-the-art review is to provide a general overview of recent research on time distribution and second language (L2) learning with special implications for classroom settings. Several studies have been performed to examine how to best distribute the hours of L2 practice to maximize learning by comparing conditions that…

Heritage languages (HLs) are acquired in contexts of unbalanced input, or situations in which children receive primary exposure to the family/HL and experience an abrupt shift after the child begins formal schooling. As a consequence, HL speakers normally become more dominant in the environmental language, while the development of the HL is…

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…

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…

Immersion programs have long been considered the gold standard for school-based language revitalization, but surprisingly little attention has been paid to the quantity and quality of the input that they provide to young language learners. Drawing on new data from three such programs (Kaqchikel, Western Subanon, and Maori), each with its own…

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.…

The interaction between input frequency and constructional interference receives little attention in second language (L2) research. Two studies were conducted to test the effect of this interaction. Study 1 examined effects of both Zipfian frequency (ZF) and balanced frequency (BF) on L2 learning of English subject-extracted relative clauses…

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…