We investigate concrete acquisition theories for a derived approach to linking theory development and explore to what extent two prominent linking theories in the syntactic literature--UTAH and rUTAH--can be derived from the data that English-learning children encounter. We leverage a conceptual acquisition framework that specifies key aspects of…

How early do children produce multiword utterances? Do children's early utterances reflect abstract syntactic knowledge or are they the result of data-driven learning? We examine this issue through corpus analysis, computational modeling, and adult simulation experiments. Chapter 1 investigates when children start producing multiword utterances;…

There is growing evidence that the grammatical errors reflected in the speech of young children are often related to the nature of the input in the ambient language. Although theoretical frameworks differ in the degree to which input plays a role, there is acknowledgment that children require more input than previously assumed to resolve apparent…

How do children learn the meaning of words like "pretty" and "tall," which are not only gradable and context dependent (Kennedy & McNally 2005), but encode speaker subjectivity? Despite their complex semantics (Stephenson 2007; Lasersohn 2009; Bylinina 2014), these and other adjectives like them, are some of the most…

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…

The Less-Is-More hypothesis was proposed to explain age-of-acquisition effects in first language (L1) and second language (L2) learning. We scrutinize different renditions of the hypothesis by examining how learning outcomes are affected by (a) limited cognitive capacity, (b) reduced interference resulting from less prior knowledge, and (c)…

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 acquire language in conversation. This is where they are exposed to the community language by more expert speakers. This exposure is effectively governed by adult reliance on pragmatic principles in conversation: Cooperation, Conventionality, and Contrast. All three play a central role in speakers' use of language for communication in…

Purpose: In typical development, distributional cues--patterns in input--are related to language acquisition processes. Statistical and implicit learning refer to the utilization of such cues. In children with intellectual disability, much less is known about the extent to which distributional cues are harnessed in mechanisms of language learning.…

This study investigated the predictions of two approaches to second language acquisition. According to the usage-based approach, learner knowledge results from the strengths and weaknesses of input-driven statistical learning. According to the learner-varieties approach, pragmatic communication principles and language-internal constraints play…

The traditional Philadelphia allophonic /ae/ system (henceforth: PHL shown in (1) below) is characterized by a set of complicated conditioning factors and a dramatic acoustic distinction between the two allophones. In recent years, some Philadelphians have begun to exhibit a new allophonic system (NAS, shown in (2) below). Like PHL, NAS is…

A recurring question in the literature of heritage language acquisition, and more generally of bilingual acquisition, is whether all linguistic domains are sensitive to input reduction and to cross-linguistic influence and to what extent. According to the Interface Hypothesis, morphosyntactic phenomena regulated by discourse-pragmatic conditions…

An in-depth examination of the acquisition of grammatical gender has not previously been conducted for Irish, an endangered indigenous language now typically acquired simultaneously with English, or as L2. Children acquiring Irish must contend with the opacity of the Irish gender system and the plurifunctionality of the inflections used to mark…

In recent decades, a growing number of children have been diagnosed with autism spectrum disorder (ASD), a condition characterized by social interaction deficits and language impairment. Yet the precise nature of the disorder's impact on language development is not well understood, in part because of the language variability among children across…

The central claim in Amaral and Roeper's (this issue; henceforth A&R) keynote article is that everyone is multilingual, whether they speak one or more languages. In a nutshell, the idea is that each speaker has multiple grammars or "sub-sets of rules (or sub-grammars) that co-exist". Thus, rather than positing complex rules to…