This book presents a new methodology for facilitating the acquisition of second languages in a natural way. This methodology aims to facilitate the acquisition of a second language in the same way that a child acquires his mother tongue, taking into account the characteristics of the environment of the acquisition of an L2, which in most cases is the classroom. These pedagogic principles have been obtained through a detailed study of infant and children's developmental psychology and the infant-directed speech (IDS), also known as Motherese. The book also provides with the main criticism different methods and approaches had had over the years and explains why this method overcomes these criticisms to teach a second language effectively