This document discusses Content ESL or English for Specific Purposes (ESP). It defines ESP as focusing on meeting the language needs of learners for their jobs or studies. ESP is often used with adult learners and teaches intermediate to advanced language skills. Examples are given of ESP for healthcare workers. The origins and growth of ESP are outlined. Course design principles for ESP emphasize using authentic materials and activities to promote real-world language use. Teachers are advised to observe workplaces and adapt materials to exactly meet learners' needs.