L1, L2 and L1+L2 subtitles in videos in L2 classroom settings: an investigation of teachers' and students' attitudes towards the use of L1, L2 and L1+L2 subtitles in the L2 classroom is a Master's work for researchers and students who are interested in L1 use in the L2 classroom and the use of videos and subtitles in the L2 classroom. It is also a right book for teachers to refer to in their L2 teaching settings. Subtitles in videos are widely used in the L2 classroom and in daily life in China. There are different types of subtitles: subtitles in the audience's first language (L1), subtitles in their second language (L2), and subtitles in both their first language and their second language (L1+L2). The purpose of this research is to fill the literature gap regarding student and teacher attitudes towards bilingual (L1+L2) subtitles, by comparing L1-only or L2-only subtitles in listening comprehension and vocabulary learning in the L2 classroom.