The purpose of this thesis comes from the problems found by the researcher from Kampus Mengajar 6. This is a way of learning vocabulary that seems less attractive to students, even though it is important for students to learn vocabulary from an early age. This thesis presents research on solving this problem, specifically teaching vocabulary using the Duolingo application. The researcher discusses two problems, those are how to teach vocabulary using the Duolingo application and how students perception about it. This research uses qualitative research methods, with the results of the qualitative data collected being processed into descriptive explanations. There are three instruments in this research, namely observation, questionnaires and interviews. This research was attended by all grade 6 students at SD Negeri Banjarmlati 2 Kediri. The results of this research show that teachers need to teach with various techniques to teach vocabulary with the Duolingo application and Duolingo Application is suitable for additional programs because the material taught is not suitable if implemented directly into the material taught from the school curriculum. The results regarding students' perceptions of using the Duolingo application as a vocabulary learning media are positive. Many students' perceptions agree that this application is easy to use and motivating to learn English. Apart from that, the researcher faces challenges such as students not bringing their own cell phones and unstable internet access. For future researchers, these challenges need to be considered when developing researchers.

Key words: Teaching English Vocabulary, Duolingo Application, and Student’s Perception.