The present study aims to measure the students' attitudes towards tilizing an Artificial Intelligence -based app of Duolingo, an English language application in developing English skills as a foreign language among primary school pupils during distance learning during the pandemic. To fulfill the purpose of the study, four instruments were constructed; a questionnaire designed by the researcher to determine the skills needed at this stage, a pre-post English test, and an online interview to measure pupils' attitudes towards Duolingo for a self-learning mode of distance education. The study adopted the survey design, and the validity and reliability of the study instruments were established before their use in the study. The sample of the study consisted of 150 pupils from K-12 across the United Arab Emirates, where 60 pupils represented the fifth grade in primary school in Sharjah and 90 represented other grade levels across the country. The Mobile-assisted language learning (MALL) using Duolingo program training was administered to the first group as a pilot study during the academic year 2019-2020 for 9 months, whereas the other group received the training during a summer camp for two months with additional languages other than English. Results of both groups revealed that Mobile-assisted language learning (MALL) using the Duolingo app led to significant improvement not only in pupils' English as a Foreign Language (EFL), but also an enhancement in their motivation toward learning other languages. In conclusion, the study introduced recommendations and implications for the future of learning English.