This paper analyzes a national technology and education program in Uruguay known as Plan Ceibal. This work studies a sample of over 105,000 students from 4th, 5th, and 6th grade of public primary education in that country. This work aims to assess the impact of technology on teaching and learning of English. The method adopted is based on log-file data to compare two different modalities of English teaching (a face-to-face and a blended model). Additionally, we explored the correlation between a common measure of online engagement when using the Learning Management System (LMS) and an adaptive English assessment. We examined the impact of the teaching modalities on the students engagement and to what extent the engagement can contribute to enhance the student learning of English. This work documents the steps followed to elaborate the common measure of engagement to ensure transparency and its replicability (or improvement). A strength of this work, in comparison with previous studies, is the number of cases analyzed as well as the age of the target population (primary school students). The results indicate that engagement is affected by at least three key factors: socio-cultural context, teaching modality, and the role that teachers play. In fact, the higher the engagement level, the larger the proportion of students who achieve a better learning outcome in the assessment. This study shows that the use of LMS enhanced the learning experience when this tool is integrated within the ecosystem of the teaching and learning process. The findings of this study are consistent with previous works in the field, for instance: the relevance of the context as well as the role of teaching. Although the measurement of engagement can help to understand students performance noteworthy that as a stand-alone dimension it is a poor predictor of performance. To consider additional factors associated with learning is still necessary.