Resumen en español

This book is the result of the hard work of both the professors and the students of the Emphasis on English Didactics at Universidad Externado de Colombia. It is important to acknowledge that the professors Núñez-Pardo and Téllez-Téllez through this Emphasis have become pioneers in the field of ELT Materials Development. They have contributed to construct a body of knowledge which establishes a dialogue between themselves and other national scholars such as Rico and Gómez with international experts, such as Gray, Littlejohn, Masuhara, and Tomlinson, among many others.