We provide an account of the developmental trajectory of Emirati Arabic negation particles. We treat the non-verbal predicate negator (NVPN) "mub" as a negative copula, in contrast to the verbal predicate negator (VPN) "maa," which encodes sentential negation in verbal and existential contexts. The analysis is supported by…

Languages differ regarding the depth, structure, and syntactic domains of recursive structures. Even within a single language, some structures allow infinite self-embedding while others are more restricted. For example, when expressing ownership relation, English allows infinite embedding of the prenominal genitive "-s," whereas the…

Aspectual and mood morphology are vulnerable domains in adult heritage speakers. This paper investigates the root of such vulnerability within the domain of Turkish evidentiality system by comparing 20 second-generation adult and 20 school-age child Turkish heritage speakers to 20 first-generation immigrants (main input providers for child…

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…

The present study examines the mechanisms of lexical case acquisition in Russian by two-to-five-year-old Russian monolingual (n = 54) and Russian-English bilingual children (n = 38). Participants performed a picture-based sentence completion task. Sentences were constructed to elicit production of real Russian words (n = 24) and nonce words (n =…

In this article, we propose a reconceptualization of the principles and parameters (P&P) framework. We argue that in lieu of discrete parameter values, a parameter value exists on a gradient plane that encodes a learner's confidence that a particular parametric structure licenses the utterances in the learner's linguistic input. Crucially,…

Previous research on 4-6-year-olds' interpretations of adjunct control has observed non-adult-like behavior for sentences like "John called Mary before running to the store." Several studies have aimed to identify a grammatical source of children's errors. This study tests the predictions of grammatical and extragrammatical accounts by…

Previous research suggests that toddlers can rely on distributional cues in the input to track adjacent and nonadjacent grammatical dependencies. It remains unclear whether toddlers understand the hierarchical phrase structures that determine the corresponding grammatical dependencies. We addressed this question by testing toddlers on two…

This paper revisits the longstanding observation that children produce modal verbs (e.g., must, could) with their root meanings (e.g., abilities, obligations) by age 2, typically a year or more earlier than with their epistemic meanings (e.g., inferences). Established explanations for this "Epistemic Gap" argue that epistemic language…

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…

In two artificial grammar learning experiments, we tested the learnability of tonal phonotactics forbidding non-domain-final rising tones (*NonFinalR) against the phonotactics banning non-domain-final high-level tones (*NonFinalH). We propose that a firm phonetic ground drives a presumably innate inductive bias favoring *NonFinalR and against…

The concept of an output-driven map formally characterizes an intuitive notion about phonology: that disparities between the input and the output are introduced only to the extent necessary to satisfy restrictions on outputs. When all of the grammars definable in a phonological system are output-driven, the implied structure provides significant…

The Spanish subjunctive mood (SUBJ) is said to be highly vulnerable in heritage language (HL) acquisition. However, there is little controlled research on HL-speaking children acquiring the various Spanish SUBJ contexts, so we do not have a clear picture of when, how, or why heritage speakers (HSs) develop in the SUBJ as they do. This study tests…

Children begin to learn abstract rules at an early age, in an implicit way, without access to rule descriptions. They rely on specific rule instances that they encounter. However, rule instances often co-occur with rule-inconsistent instances. One kind of inconsistent input, non-application instances, constitutes a learnability problem. For…

An evaluation measure (EM) guides a learner's choice of grammar when more than one is compatible with available input. EM must be universal, so children receiving comparable input acquire comparable grammars. It must favor the choices children actually make. The theoretical shift from rule-based grammars to principles-and-parameter-based grammars…