This article presents a discussion on the importance of digital tools that can be used in the process of teaching and learning additional languages at a time of emergency education. It is a bibliographic study with a qualitative approach, carried out with a search in different databases with criteria to select texts for analysis. Among the tools used, we highlight an analysis related to Duolingo, from a perspective of the CALL (Computer-Assisted Language Learning) approach, based on technical, theoretical, and social criteria. The results point to the potential of this tool due to the gratuity, multiplatform access, gamified interface, and activity management by the teacher through Duolingo Schools, in addition to the possibility of certifying the level of proficiency in the English language. The discussion also shows some limitations and social issues that highlight the precariousness of online education before and during the context of a global pandemic