The current article studies the competencies of plurilingual students and how these competencies are exploited in the learning of French as a Foreign Language. Adopting a translanguaging theoretical approach, we argue that learners of foreign languages who already speak at least one other language have some linguistic competencies which manifest during their learning of the French language. Through observation of learners of French at the University of Ghana Business School and analysis of their written production, we confirm that some of these plurilingual competencies in students are demonstrated in the nature of the errors identified. The paper therefore recommends that learners' existing competencies be taken into account and built upon when developing lessons for the foreign language classroom and during classroom delivery.