Materials adaptation refers to altering teaching materials to better suit learners' needs, the teacher's demands, and administrative purposes. It involves changing internal characteristics of coursebooks to maximize appropriateness in different contexts. Adaptation aims to achieve congruence between materials, methodology, learners, objectives, language context, and the teacher's style. It may involve modifying language practices, texts, skills, or classroom management. Reasons for adaptation include materials not meeting goals, failing to engage learners, or lacking necessary resources.