First of all, I would like to express my gratitude to all my students for their active participation in learning Khmer language. Their feedback on my courses helped me to develop and tailor this online textbook according to their needs and concerns.
I am deeply grateful to Regina Gong and her team members, who work for Open Educational Resources (OER) at Michigan State University Libraries, for their support. I must also thank the Department of Linguistics, Languages, and Cultures at MSU, particularly Danielle Steider and Dr. Ranjan, for their advice and many helpful suggestions during the preparation of this textbook.
Last, but not least, my thanks to my family. This work is dedicated to them: particularly to my father, my mother, and my wife, who have always been supportive.