Analysis of Cohesion in Academic Writing by Undergraduate Students at Ahmadu Bello University

Textual cohesion, encompassing the grammatical and lexical mechanisms that link sentences and paragraphs into coherent discourse, is a fundamental component of academic writing competence that is frequently problematic for Nigerian ESL undergraduate writers. This study analyses cohesion in academic essays produced by undergraduate students at Ahmadu Bello University, Zaria, focusing on the distribution and appropriateness of reference, conjunction, and lexical cohesion devices. A corpus of one hundred and eighty essays submitted for English Studies courses across three departments was assembled and subjected to cohesion analysis using Halliday and Hasan's framework as extended by recent academic writing research. Reference device analysis reveals that pronoun reference ambiguity is the most frequent cohesion error, occurring at an average of three instances per essay, often creating interpretive difficulty at paragraph boundaries. Conjunction use shows over-reliance on additive conjunctions, particularly and and also, with adversative and causal conjunctions significantly underused relative to their expected frequency in academic argumentation. Lexical cohesion analysis shows limited reiteration through synonymy and superordination, with simple repetition accounting for most lexical cohesion attempts. Higher-rated essays show significantly richer conjunction variety and more systematic lexical cohesion deployment. The study recommends that writing instruction at Ahmadu Bello University include explicit cohesion device training with particular attention to adversative and causal conjunction use. Keywords: cohesion, academic writing, undergraduate essays, Ahmadu Bello University, ESL writing.