When learning a language, language learners endeavor to enhance their language skills such as listening, speaking and writing.However, it would be difficult to determine what might positively or negatively affect a skill. Therefore, in this book, we examine if listening as a skill is influenced by two factors; namely motivation and metacognitive strategies. This book aims to investigate which might affect listening proficiency more? Is it "working smarter" by employing metacognitive learning strategies or by "working harder" that derives from learners' motivation?