Second language acquisition and the multilingual mind: overview

Book section : Chapter

The field of second language acquisition (SLA) focuses on a remarkable human capacity to learn not just one language, but to acquire multiple languages, in multiple modalities—whether spoken, written, or signed—and to do so across the lifespan. It examines the cognitive processes involved in learning additional languages and the models of how multiple languages coexist in a single mind. Through these models, researchers seek to understand what emerging and functional bilinguals know, how and under what conditions they construct and organize that knowledge, and how they deploy it under the time pressures of interaction and communication. Although the terms SLA, bilingualism, and multilingualism stem from slightly different research traditions, they are used synonymously here to refer to the learning, knowledge, and use of more than one language.

The section does not aim to provide a historical overview of all the concepts and approaches that have shaped the field. Instead, it illustrates some of the key theoretical and empirical strands of current research. In doing so, it brings together findings from a range of disciplines, including applied linguistics, linguistics, psycholinguistics, psychology, and cognitive neuroscience. Scholars working in these fields often publish in different areas of the literature—often outside of applied linguistics—and focus on different linguistic levels, phenomena, and influencing factors. Yet, these diverse perspectives all contribute to our understanding of the complex phenomenon that is cognitive second language acquisition and the multilingual mind.

Authors: Trenkic, D; de Bruin, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Host title: The Encyclopedia of Applied Linguistics
• Publication date: 2026-03-26
• DOI: 10.1002/9781405198431.wbeal1350.pub2
• EISBN: 9781405198431
• ISBN: 9781405194730
• Language: English
• Keywords: second language acquisition; multilingual mind; bilingualism; multilingualism; bilingual processing; cognition
• Subtype: Chapter