This document discusses the nature of language and applied linguistics. It provides definitions of language from various scholars and outlines shifts in theories of language over time. A key shift was from viewing language as a system of forms to recognizing its communicative function. Applied linguistics is defined as identifying and solving language-related problems, and can be applied to areas like language teaching and learning, acquisition, assessment, and more. Linguistics contributes to education by helping teachers reshape their views of language and learning.