This dissertation articulates and defends a view about linguistic competence called 'variabilism'. According to variabilism, the epistemic demands of full linguistic competence vary in a particular way. More specifically, variabilism holds that different individual lexical application conditions (individually essential metaphysical ways of being…

Advances in Natural Language Processing (NLP) over the past decade have largely been driven by the scale of data and computation used to train large neural network-based models. However, these techniques are inapplicable to the vast majority of the world's languages, which lack the vast digitized text datasets available for English and a few other…

Previous studies show that linguistic information and talker information interact during processing. Familiarity with a language facilitates talker processing, and familiarity with a talker's voice facilitates linguistic processing. To probe the factors involved in talker processing, researchers examined how individual differences in reading…

Embodied models of language comprehension assume that words become associated with sensorimotor experiences during word learning. Novel word learning paradigms may provide insight into embodied effects, but studies in this domain have yet to account for how concepts and information known in first language (L1) might influence the sensorimotor…

One of the fundamental questions in the field of language acquisition is a learnability problem, which considers how learners acquire certain aspects of language which are not directly provided in the input or whose referents are not readily observable. This dissertation investigates Japanese children's acquisition of various linguistic phenomena,…

The assessment data in La Frontera School District suggests a need for improving instructional practices for middle school emergent bilingual migrant students' language and reading development. One possible solution to the language and literacy issues maybe introducing cognates. Cognates are words with identical or similar orthography and meaning…

When acquiring a second language, learners must become able to perceive the difference between novel sounds ("discrimination") and also associate strings of sounds with distinct vocabulary items ("lexical encoding"). Recent research has questioned whether discrimination is a sufficient or necessary condition for encoding, and…

Vocabulary knowledge and speed of lexical access are early components of linguistic skill that co-develop rapidly in the first two years of life. Evidence suggests that these components are foundational for downstream linguistic and cognitive skills and that early individual differences set the stage for a developmental cascade throughout the…

Growing up in the digital era, young children are exposed to numerous educational applications and programs, some with well-designed curricula and others focused more on entertainment or game-like qualities. With the increasing popularity of mobile language-learning applications among young children, this dissertation raises a crucial question: do…

Dialogue systems, commonly called as Chatbots, have gained escalating popularity in recent times due to their wide-spread applications in carrying out chit-chat conversations with users and accomplishing tasks as personal assistants. These systems are typically trained from manually-labeled data and/or written with handcrafted rules and often, use…

Language can alter our mental conceptions of space, time, and categories. While there is compelling evidence that thought can be shaped by syntactic, morphological, and lexical features of a language, less is known about the impact of phonology on thought. This dissertation uses novel objects (alien cartoon figures) and pseudoword names in three…

Generalization is the ability to apply regularities to novel instances, for example, correctly guessing that the plural for the novel English word 'wug' should be 'wugs'. Early language learners make overgeneralization errors like 'mouses', applying regularities beyond their attested uses. Theories concerned with the question of how learners learn…

Conceptual Metaphor (CM; e.g., Lakoff & Johnson, 1980, 1999; Kovecses, 2020) is central to our thinking and ubiquitously manifested in our language. Given its importance, the teaching of conceptual metaphors has gained much attention in Cognitive Linguistics and Applied Linguistics. While most empirical studies have focused on specific aspects…

Individuals with lower proficiency in a second language tend to produce more disfluent speech patterns in the second language. Speech disfluencies refer to interruptions in the forward flow of speech and are distinct from the colloquial use of "fluency," to characterize knowledge of a language. Prior research indicates that some speech…

Referential expressions such as pronouns are frequently used in conversations, and native speakers seem to understand who these expressions refer to effortlessly. Although the process of pronoun resolution seems to be easy, interpretations of pronouns are dependent on various sources of information from the discourse including morphosyntax (e.g.,…