Due to the evolution of technology, this study focuses on the use of technology in order to promote language learning. Duolingo is one of the modern applications that facilitate acquiring a second language. Hence, the study aims to confirm the hypothesis that Duolingo helps promote acquiring two languages simultaneously for beginners. It is a mixed-method study including observation, assessment, and interview. It is also a case study that involves one participant who used Duolingo to learn Spanish and English simultaneously for two months. The participant is a male school student whose age is 12 years old, and he lives in Riyadh, Saudi Arabia. After collecting the data, they were analysed and described to have the final results. At the end, the results displayed that Duolingo can promote acquiring two languages for beginners, but it has limitations. Thus, it is recommended to develop Duolingo for advanced levels as well as for English language learners.