Teachers need a strong understanding of educational linguistics to effectively communicate with students, support language development, and make fair evaluations. The document outlines five reasons why: 1) As communicators, teachers must understand differences in language use and structure instruction for clarity. 2) As educators, teachers must assess student knowledge and design instruction to expand linguistic skills. 3) As evaluators, teachers' judgments have serious consequences, so they need linguistic knowledge to fairly assess differences. 4) As educated individuals, teachers should understand language as an important part of human development. 5) As socializing agents, teachers must recognize home language practices to promote school language without devaluing student backgrounds. Overall, educational linguistics knowledge is crucial for teaching diverse students