The book is an in-depth and comprehensive analysis of the case of language in education reform and language policy controversies of Hong Kong over the initial two decades after 1997. It is a scholarly monograph of conscientious educators and researchers who have been active during the education reform, collaborating with different parties on school development and classroom teaching experiments. This book provides a multiple-perspective investigation into the education and language matters. Besides socio-political perspectives, this book also emphasizes the frontline educational and practical perspectives. The book explores the benefits and effective methods of mother-tongue and multi-lingual teaching that have emerged in the period.  Based on the problematic experience of language purism and bifurcation in the reform, the book argues for an inclusive multilingual education policy with mother-tongue as the core. This book provides potential solutions and good practices to tackle the complex issues brought about by medium of instruction policy reforms in post-colonial times.