ABSTRACT This research study sought to determine and compare the level of negative phonetic transfer interference of both English as the first foreign language acquired (L2) and Spanish as the mother tongue (L1) in the in telligibility of oral expression of French as their third language (L3), with a random sample of 15 students of French from the Department of Languages and Linguistics of the School of Secondary Education of the Faculty of Education and Communication Scien ces of the National University of Trujillo, to whom a questionnaire was applied to record their oral production. This research is descriptive comparative in nature and, as such, was developed in two phases: the first consisted in observing how the students articulate the French phonemes and sounds; and in the second, the degree of Spanish and English interference in the oral expression of French was compared. The stat...