This document provides an introduction to applied linguistics. It begins by defining linguistics as the scientific study of language and its forms, meanings, and uses. Applied linguistics is then introduced as utilizing linguistic knowledge to solve real-world problems related to language learning, teaching, literacy, policy, and more. The relationship between theoretical linguistics, interdisciplinary linguistics, and applied linguistics is explored. Finally, the document outlines the focus and issues to be discussed in this applied linguistics course, including foreign language teaching methods and syllabus design.