This book offers an in-depth account of the meaning of grammatical elements representing evidentiality in connection to modality, focusing on theoretical/formal perspectives by eminent pioneers in the field and on recently discovered phenomena in Korean evidential markers by native scholars in particular. Evidentiality became a hot topic in semantics and pragmatics, trying to see what kind of evidential justification is provided by evidentials to support or be related to the ‘at-issue’ prejacent propositions. This book aims to provide a deeper understanding of such evidentiality in discourse contexts in a broad range of languages such as American Indian, Korean and Japanese, Turkish and African languages over the world. In addition, an introduction to the concept of evidentiality and theoretical perspectives and recent issues is also provided.