Exploring Code-Switching and Phonological Variation in Urban Multilingual Speech: A Corpus-Based Analysis of Nigerian English and Yoruba Interaction

Project Abstract

This study investigates code-switching and phonological variation in urban multilingual speech through a corpus-based analysis of Nigerian English and Yoruba interaction, aiming to reveal the functional, phonetic, and socio-phonetic patterns that emerge in everyday talk. By compiling and annotating a large, naturalistic corpus of spontaneous conversations gathered from diverse urban settings in southwestern Nigeria, the project examines how speakers negotiate identity, solidarity, and social distance through language alternation, while also tracking phonological adaptation, segmental shifts, and prosodic cues that accompany language switching. The methodology integrates advanced phonological transcription with compelled and unforced code-switching analyses, leveraging automated speech recognition and manual verification to ensure high transcription fidelity across both Nigerian English and Yoruba phonological systems. The research tests a set of hypotheses regarding the correlation between interlocutor attributes (age, gender, socio-economic background), topic domains, and code-switching frequency, as well as the directionality of language shifts (e.g., English to Yoruba, Yoruba to English) within turn-construction units, adjacency pairs, and topic-comment structures. A key objective is to identify phonological variants that arise specifically in switching contexts, including loanword adaptation, borrowing-induced phoneme inventory changes, and allophonic adjustments conditioned by preceding or following segments from the contrasting language. The study also investigates segmental inventory convergence in bilingual bursts, nativization processes in phonotactics, and the role of tone and intonation in signaling switch boundaries and emphasis. Data analysis employs a mixed-methods framework quantitative modeling to estimate code-switching rates, lexical borrowings, and phoneme distributions, complemented by qualitative discourse-analytic and sociolinguistic investigative techniques to interpret speaker agency, stance, and social meaning. The corpus enables cross-register comparisons across informal street talk, market interactions, workplace conversations, and community events, providing insights into how urban multilingual speakers manage social norms and power relations through language choice. Anticipated findings include systematic patterns of code-switching tied to topic domains (e.g., commerce, family, education), predictable phonological adjustments in loanword tokens, and phonotactic constraints that shape switch feasibility. The research contributes to theories of bilingual discourse, phonology of contact varieties, and sociolinguistic identity construction, offering practical implications for language policy, education, and speech-technology development in multilingual Nigerian contexts. By delivering a richly annotated resource and a set of generalizable models for code-switching dynamics, the study advances understanding of how Nigerian English and Yoruba interact in dynamic urban speech, highlighting the complex interplay between linguistic structure and social meaning in multilingual environments.

Project Overview

What This Project Is About

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A plain-language overview of the topic and what the project investigates.

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The Problem It Addresses

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What problem or gap this project tackles and why it matters to the field or society.

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Objectives of the Project

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1. Identify where languages mix in urban speech.
2. Describe basic patterns of code-switching between Nigerian English and Yoruba.
3. Document common pronunciation changes (phonological variation) seen in multilingual talk.
4. Build a small, usable dataset (corpus) from real conversations.
5. Provide insights that can help language education and policy discussions.

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What You Will Do Step by Step

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1. Learn basic methods for collecting speech from speakers in urban Nigerian settings with consent and ethical considerations.
2. Record short conversations or interviews that include both Nigerian English and Yoruba.
3. Transcribe the recordings and label when languages switch and how sounds change.
4. Summarize common switching situations and phonetic patterns in simple terms.
5. Review existing studies to compare findings with what others have described.
6. Organize the data into a small searchable collection (corpus).
7. Analyze trends by describing how often switches occur and under what contexts.
8. Prepare a simple report and presentation for stakeholders or classmates.

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Expected Outcome

Expected results include a clear description of how often speakers switch languages, what kinds of sounds shift, and a ready-to-use dataset. The project aims to provide practical insights for educators, linguists, and policymakers interested in multilingual urban speech.