Language Diversity and National Identity in Nigerian Presidential Address Discourse: A Longitudinal Critical Discourse Analysis 1999 to 2024

This study presents a longitudinal critical discourse analysis of the construction of national identity and the negotiation of language diversity in Nigerian presidential address discourse over the period 1999 to 2024, covering the full democratic dispensation from the return to civilian rule. Presidential discourse is a primary site of national identity construction in Nigeria, and the linguistic strategies through which successive administrations have addressed the country's ethnolinguistic diversity provide unique insight into the ideological evolution of national identity politics. The research constructs a corpus of 180 presidential addresses, including inaugural speeches, Independence Day addresses, and budget presentations, drawn from four presidential administrations. The corpus is analysed using van Dijk's discourse and ideology framework supplemented by Wodak's discourse-historical approach. The analysis tracks the discursive construction of national unity and diversity across administrations, examining metaphorical framing of nationhood, the deployment of indigenous language phrases as identity signals, the management of ethnic references, and the ideological positioning of linguistic diversity as resource or problem. Findings document significant ideological variation across administrations, with northern-origin presidencies showing higher frequencies of Arabic and Hausa insertions while southern-origin presidencies show greater deployment of English cosmopolitan registers. Across all administrations, a dominant assimilationist ideology frames linguistic diversity as a challenge to be managed rather than a resource to be valorised. The research makes an original contribution to the discourse analysis of postcolonial nationalism in Africa. Keywords: national identity, presidential discourse, critical discourse analysis, linguistic diversity, Nigeria.