This study is concerned with the investigation of the phenomenon of lexical cognateness and the transferability of French-English cognates from French (L2) to English (L3) by Burundian university students of English whose L1 is Kirundi, a Bantu language. The study examines cognate lexis according to the criteria of etymological origin as well as form, sound, and meaning correspondence and contrasts. It also investigates how 'false cognates' come about through semantic change and suggests the usefulness of examining French-English cognates in terms of 'cross-linguistic sense relations' such as synonymy, hyponymy, homonymy, and polysemy. These various features have been adopted as exploratory and classificatory devices in order to provide a linguistic framework for a systematic description and classification of French-English cognates. The investigation concludes that (I) apart from a few exceptions described as 'accidental cognates', French-English cognates are etymologically and historically related, (ii) false cognates have resulted from various forms of semantic change in the course of time such as the extension or narrowing of the original meaning, change in denotative meaning, and shift from denotative to figurative or emotive meaning, and (iii) a good number of French-English cognates can be described as cross-linguistic synonyms and hyponyms. The experimental part of the study comprises four tasks (sentence completion, acceptability judgement, multiple choice, and word association) all designed to assess the transferability of cognates from French to English. One hundred and twenty-six subjects selected from four different years of study in the Department of English language and literature of the University of Burundi took part in the experiments. The findings of the study support our three research hypotheses.