This research has the aim of highlighting the importance of motivation in the process of learning English as a foreign language. For that purpose, some factors that affect motivation are described, using as a starting point the answers obtained from a questionnaire given to students in their fourth year of compulsory secondary education. The main conclusions of the research show the fundamental role of factors such as the teacher, the four skills, students' interests and daily habits, among others. Finally, some guidelines for a teaching methodology are proposed with the intention of future development.