In recent years, the development of literacy has been the subject of research from various scientific fields, and their results affect the way language teaching is approached in primary school. Within this framework, the aim of this book is to analyze the different theoretical approaches to literacy development in early childhood, in order to synthesize these theories and highlight the knowledge and skills that are developed or need to be developed at this age, which is considered one of the most important periods in literacy development. Additionally, the factors that contribute to its development and influence it are presented through the results of research in both Greek and international literature. This analysis is connected to teaching approaches for language teaching as they have appeared in Greek education in the past two decades. The main assumption adopted in the chapters of the book is that language is used for communication, and therefore the main goal of language teaching is to enable students to effectively use oral and written language in various communication situations. It is argued that the comprehension and production of texts, both oral and written, are the main goal of teaching, and an effort is made to highlight the skills related to comprehension and production that can be developed in early school age. This does not mean that important findings regarding letter knowledge, phonological awareness, word and sentence recognition and writing are ignored, as all of these are connected to both comprehension and production of texts.