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…

The aim of the paper is to present the results of a research project called 'Tell Me', conducted from October 2018 to March 2020. The project focused on Bengali children living in Venice, Italy, and aimed to describe (1) children's languages in the home environment and at school; (2) the quality and quantity of input they receive in every language…

The impact of the lexicons that were often used in the past will be eroded due to the environmental conditions that surround them. This study has examined the critical condition in Balinese lexicon extinction. There are some Balinese language vocabularies that are almost extinct by the current generation due to cultural hegomonization. The…

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 "wanna" facts are a classic Poverty of Stimulus (PoS) problem: "Wanna" is grammatical in certain contexts ("Who do you want PRO to play with?") but not others ("Who do you want who[strikethrough] to play with you?"). On a standard analysis, "contraction" to "wanna" is blocked by some…

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…

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…

This paper presents an argument for how second language acquisition (SLA) research should be carried out if a researcher is genuinely interested in learner grammar (i.e., knowledge of language), its acquisition and use. SLA research has expanded greatly over many years and currently spans many subfields, but researchers share one main goal: to…

I review the classic literature in generative grammar and Marr's three-level program for cognitive science to defend the Evaluation Metric as a psychological theory of language learning. Focusing on well-established facts of language variation, change, and use, I argue that optimal statistical principles embodied in Bayesian inference models are…

Languages spoken in larger populations are relatively simple. A possible explanation for this is that languages with a greater number of speakers tend to also be those with higher proportions of non-native speakers, who may simplify language during learning. We assess this explanation for the negative correlation between population size and…

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…

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…

This paper presents an experimental study of the rarely explored question of how input through instruction interacts with L2 acquisition at the level of modular linguistic knowledge. The investigation focuses on L2 knowledge of the English polarity item "any," whose properties are only partially covered by typical language-teaching…

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…