Effects of subtitle format on incidental vocabulary acquisition: Size and position sequence of L1 and L2 subtitles

There has been extensive research on the impact of subtitles on incidental vocabulary acquisition (IVA) in video watching, but investigation on the influence of relative font size and position sequence of bilingual subtitles on IVA outcomes is scarce. Additionally, we examined the effect of video genres on vocabulary acquisition and the moderating roles of participants' existing vocabulary knowledge and English proficiency. Eighty Chinese-speaking college EFL learners participated in this study to measure the effects of viewing two videos on form recognition and meaning recognition. The findings revealed that E/C Same Size (English above, Chinese below, same size) lead to higher scores than C/E Smaller C (Chinese above, English below, Chinese smaller) in the word meaning recognition test. However, no significant differences were found in vocabulary acquisition between comedy and edutainment. However, participants' vocabulary size moderated the effect of subtitle format on word meaning learning, indicating that existing vocabulary knowledge plays a role in how learners benefit from different subtitle formats.