Investigation into the differential effects of subtitles (first language, second language, and bilingual) on second language vocabulary acquisition
Video recordings can be subtitled in three ways: with first language (L1) subtitles, with second language (L2) subtitles, or with first language plus second language (bilingual or L1+L2) subtitles. The first two types of subtitles are widely discussed in previous research with regard to how they affect language learning. However, the effects of bilingual subtitles have not been widely studied. This study aims to examine the pedagogical effects of bilingual subtitles on vocabulary acquisition in the L2 classroom. A seven-week quasi-experimental study was conducted with four English-major classes in year-3 in a Chinese university: three experimental groups and one control group. Students in the three experimental classes were exposed to three documentary films on very similar topics with the three different types of subtitles in turn. They then took a vocabulary test relating to the lexical items encountered in the films. At the end of the experiment, they were given a questionnaire to explore their opinions towards differential subtitles in relation to their language learning. The results demonstrated a significant advantage of bilingual subtitling in videos for students’ receptive vocabulary knowledge and recall at post-test and this advantage was maintained at delayed post-test. The bilingual subtitles probably are more effective than monolingual subtitles with regard to students’ vocabulary acquisition in short-term and long-term. Also, bilingual subtitles were preferred by a majority of students in respect of video understanding and vocabulary learning. L2 subtitles were favoured by more students for improving their listening comprehension. Pedagogical implications for the use of differential subtitles in the L2 classroom are discussed.