Shim, Ji YoungParlak, OzgurAbouelasaad, Shaymaa Hesham2025-06-122025-06-122025-0429.232-2025.03https://hdl.handle.net/11073/26116A Master of Arts thesis in Teaching English to Speakers of Other Languages (TESOL) by Shaymaa Hesham Abouelasaad entitled, “The Effects of Subtitles on Second Language Vocabulary Learning”, submitted in April 2025. Thesis advisor is Dr. Ji Young Shim and thesis co-advisor is Dr. Ozgur Parlak. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Language teachers have long been encouraged to integrate modern technologies into their instruction to enhance language learning, particularly through practices that can be extended beyond the classroom setting (Ercan, 2020; G‘aniyeva, 2024). One such approach involves incorporating intralingual and interlingual subtitles into audiovisual materials. This study examined the effects of intralingual (English) and interlingual (Arabic) subtitles on incidental vocabulary learning among native Arabic speakers in the United Arab Emirates (UAE), an underrepresented demographic in existing research. The study involved 125 upper-intermediate English learners enrolled in the Basic Academic Writing course (WRI 001) at the American University of Sharjah (AUS). Using a pretest-intervention-posttest design, participants were assigned to one of four groups: Experimental Group 1 (Arabic subtitles), Experimental Group 2 (English subtitles), Control Group 1 (No subtitles), and Control Group 2 (No dialogue). To analyze the data, linear mixed-effects (LME) models were fitted using the lme4 package in R (Bates et al., 2015). Results revealed a statistically significant effect in the meaning recall test, with Experimental Group 2 (English subtitles) outperforming Control Group 1 (no subtitles) when words are encountered multiple times. However, no significant differences were found between groups in the form recognition and meaning recognition tests. These findings highlight the pedagogical potential of intralingual subtitles in supporting incidental vocabulary learning and provide insights for L2 teaching strategies.en-USIntralingual subtitlesInterlingual subtitlesIncidental learningDual Coding TheoryVocabulary developmentThesis