This research aims to identify the conceptions of the bachelor's degree trainees in Modern Languages of the Javeriana University in Bogota, concerning teaching in the field of French as a Second Language (FSL), based mainly on the lesson plan elaborated during their internship. The objective is to identify the way in which the theoretical and didactic elements of the methodologies and approaches to teaching FSL - learned during their studies- have been understood and implemented in their teaching practice. To this end, this study is based on the concepts and the work carried out mainly by three recognised specialists in the didactics of languages and cultures: Christian Puren (1988), a language and culture didactician, Jean- Pierre Cuq (2005), a french linguist and didacticien, and Isabella Gruca (2005), a french teacher. In addition, we have supplemented these basic references with other theoretical elaborations and approaches close to our context and line of research. For the implementation of our study, we designed and applied semi-directive interviews in order to identify the initial conceptions concerning the teaching of FSL to the trainees in the second semester of 2019. We also developed an analysis grid with the essential principles of the methodologies and approaches to the teaching FSL, to analyse the initial conceptions of trainee teachers and their lesson plans. Thanks to the dialogue between these three tools, we have established four categories of analysis: the roles of students and trainee teachers, teaching practices in the classroom, conceptions of language and learning and culture. According to the results obtained, we found that there are certain contradictions between what the trainees express and perceive about the teaching of FSL during the interviews and what is planned in their lesson plans. Indeed, most of them state that they follow an action-oriented approach (task-based learning approach), yet in the planning of their courses, this is not highlighted. On the contrary, the emphasis always seems to be on grammar and explicit grammatical explanations. Probably, there are restrictions related to the context of the course, the pedagogical guide which requires the application of principles and the use of a specific methodology or, in some circumstances, the lack of clarity for the implementation of certain pedagogical practices in a FSL course. Finally, one of the most interesting aspects is the cultural component which is considered for them as an important part of the FSL class; however, it is not really addressed or even taken into account when they are planning the objectives and activities of the course. Keywords: Conceptions, teaching of FSL, trainees, lesson plans, analysis grid, methodologies