Beliefs about language learning is one of key areas in second language acqusition (SLA) research. This study linked beliefs with the implementation of out-of-class language-learning activities. Participants of this study were Chinese-speaking adolescent ESL learners undertaking vocational education in Hong Kong and their teachers. Results indicate that the two aspects are intimately related: Learners who regarded out-of-class language-learning activities as useful were found to possess more positive beliefs regarding their English learning. Learners who implemented out-of-class language-learning activities were found to have more positive beliefs in terms of two factors, the factor of Perceived Value and Nature of Learning Spoken English, and the factor of Self-efficacy and Expectation about Learning English. Teachers either directly or indirectly agreed that there is an association between beliefs and the implementation of out-of-class language-learning activities. This book is particularly useful for post-graduates and researchers in the field of SLA and TESOL research, as well as undergraduates who would like to further their knowledge on the two focuses of this study.