This volume is the first published collection of papers on the impact of diglossia and dialectal variations on language and literacy acquisition, impairment, and education. The authors are pioneering in this field and are leading researchers with substantial experience in conducting research in this area. A wide range of areas and languages are covered, including the US, South Africa, Israel, and various European countries. The chapters present novel data and insights regarding the role of dialectal variations on language and literacy, from a wide range of countries and perspectives. These insights have significant theoretical and practical implications. A majority of literacy learners worldwide are taught to read and write in a language variety or a dialect that is not the same as their spoken language. Not only is this the global norm, but it is probably also the greatest obstacle to literacy learning. This volume is the first published collection of papers on the role of dialect in language and literacy acquisition, impairment, and education in a variety of languages and situations across Europe, the Middle East, North America, Africa, and Asia.The authors are pioneers in this field.