Improving the quality of education is one of the aspects that the current Ecuadorian government has considered in the organic law of intercultural education. From that point of view, the Ministry of Education (2013) established a set of quality standards in order to improve the teaching-learning process in high schools. However, there are important issues that still hinder the interaction and English language acquisition in the classroom; one of those factors is class size. For that reason, the purpose of this research is to determine the effects of learning English in large classes. Determining whether large classes affect the English teaching-learning process involves the following research questions: What instructional implications do large classes have on the teaching-learning process? What social implications do large classes have on the teaching-learning process? What psychological implications do large classes have on the teaching-learning process? The responses to those questions will make possible to provide teachers and educational authorities with a set of important actions in order to improve the quality of teaching and learning English in large classes.