Learning a second language at an adult stage is a multifaceted process that entails different affective motivational variables. These variables affect the learners’ perception of his/her own L2 performance and production. One of the most important challenges that second language acquisition (SLA) research has, is to analyse the effect of different affective motivational variables at different levels of English. Thus, the thesis gathers a sample of 400, 100 of students per level of English (A1-B2). The students who participated in the study belonged to 2 different Official School of Languages, with an average age of (A1 M=38±SD=10.09; A2 M=37.36±SD=10.58; B1 M=35.84±SD=9.72; B2 M=36.89±SD=8.49). Students completed four questionnaires to measure affective emotional variables, such as motivation, anxiety, attributions, and self-concept, and they also completed three questionnaires to measure second language learning strategies, such as reading, speaking and listening. Furthermore, students completed a background questionnaire, a reading habits questionnaire and a Quick Placement test in order to place the students’ level in the study. The study shows the following results. Firstly, with regard to Affective Variables, students at A1 level show more second language learning anxiety than the rest of the levels. Besides, they also show more emotional self-concept and use more motivational strategies related with intrinsic, instrumental, self-efficacy, technological, self-regulation, and international motivation than the rest of the levels (A2, B1 and B2). Finally, students at A1 level attribute their successful outcomes to the teacher and task difficulty, whereas they attribute their failure outcomes to their lack of ability and enjoyment during the class. In addition, students at B2 level have more academic self-concept and more anxiety motivation than the rest of the levels. Secondly, with regard to the Language Learning Strategies, the results show that lower levels such as A1 and A2 rely more on memory strategies, and have fewer cognitive, compensation and social strategies. In addition, students at A1 level lack abilities to negotiate meaning, to maintain fluency; besides, these students use non-verbal strategies in a communicative interaction. Furthermore, A1 level students tend to reduce the length of their message, become less active listeners, or abandon the message. In contrast, students at A1 level show more strategies to solve problems when reading a text and they also seek for help such as teacher, dictionary, taking notes, etc, in order to comprehend the message. In addition, students at B2 levels attribute their successful outcomes to ability and enjoyment in the class. Finally, the results of the Structural Equation Modelling (SEM) shows the influence that affective motivational variables have on the language learning strategies used by students during their L2 learning process. Thus SEM shows that both internal and external motivations have an effect on students’ attributions of successful and unsuccessful outcomes, and these attributions exert an impact on the academic self-concept and anxiety dimension. Furthermore, these affective motivational variables have an overall positive effect on the reading, oral and language learning strategies.