Since the pedagogical mediation of English grammar, many teachers rely heavily on textbooks, but many of them promote memorisation rather than conscious use of grammar. Based on this premise, this article seeks to assess the effectiveness of activities for the formal conception of linguistic elements for grammar learning as a strategy to teach three speaking times in English. This study followed a mixed method design with a research-action component where researchers taught simple, continuous past and perfect present to a group of 9th year students in writing and reading classes at the Bilingüe School of Palmares, Alajuela, Costa Rica through the research activities. The data analysed consisted of the average milestones of the activities (preliminary, subsequent and final examination) and the triangulation of the perspectives of students, cooperating teachers and researchers. The results of the averages revealed an improvement at all times in the subsequent test and most of the scores remained in the final test. Through triangulation of perspectives, researchers identified these activities as positive and encouraged students’ active participation and critical thinking. The conclusions indicated a possible cumulative effect of the implementation of the activities and the need to explore the effect of these activities on students’ ability to self-monitor in a more independent practice.