This is a very fundamental textbook on Vietnamese linguistic theory, compiled by Professor Nguyễn Tài Cẩn, a highly respected scholar in the field of Vietnamese linguistics. The book offers rich academic content, incorporates modern linguistic theory, and is grounded in the practical realities of the Vietnamese language. The author systematically presents a series of key issues in Vietnamese grammar with exemplary pedagogical clarity, enabling readers to easily grasp the material—whether they are majors in linguistics, foreign-language-majored students specializing in interpretation and translation, or teachers of Vietnamese language and literature in general. This textbook is intended for students of linguistics, graduate students, doctoral candidates, secondary-school teachers, and students of Colleges of Education and pedagogical universities specializing in Vietnamese literature.