The 2nd VietCALL International Convention (VietCALL 2026)

Despite the widespread use of mobile applications for language learning, little is known about their effectiveness for developing speaking skills among Vietnamese university students. This study investigates the impact of Duolingo on the English speaking performance of English-major students in a university in Hanoi. Employing a quasi-experimental mixed-methods design, 180 students were divided into an experimental group, which supplemented regular classes with structured Duolingo speaking practice for 10 weeks, and a control group. Data were collected through speaking pre- and post-tests, questionnaires, and semi-structured interviews. Results showed that the experimental group significantly outperformed the control group, particularly in pronunciation and fluency. Students reported increased motivation and reduced speaking anxiety, though they noted limited opportunities for spontaneous interaction. The findings suggest that Duolingo can serve as an effective supplementary tool for speaking practice when integrated with classroom instruction. Pedagogical implications for MALL in Vietnamese higher education are discussed.