This book explores the intersection of writing theory, language simplification, and academic communication, with a specific focus on integrating plain English into doctoral education. Through five comprehensive chapters, the book discusses essential topics such as the principles of effective writing, the role of clarity and readability in academic texts, and the significance of plain English for enhancing scientific writing skills. Chapter 1 offers an overview of writing theory, emphasizing key concepts that impact the clarity and readability of written texts. Chapter 2 examines the importance of language simplification, particularly in scientific publishing, while Chapter 3 highlights writing challenges in target language classrooms, with a focus on writing development. In Chapter 4, the book provides the context for a groundbreaking empirical study, justifying the use of plain English in PhD language programmes. Chapter 5 presents detailed data analysis, key findings, and implications for future research, demonstrating how the teaching of plain English enhances doctoral students' writing skills, empowers them as publishable authors, and improves the overall quality of their scientific work. Given the limited research on this topic in Polish educational settings, this book is of interest to scholars and English language teachers in doctoral programmes.