From 1945 until 1987, the KMT (Nationalist) government enforced its strict Mandarin Language Policy in schools throughout Taiwan, and students were forbidden to speak local languages or dialects. Recent reversal of this policy allows schools to teach these formerly forbidden varieties. Despite some attention from scholars, it remains to explore the impact of these policies on successive generations of bilingual speakers. This study explores the perceptions of parents, grandparents, and young adults. The data show that school-based policies have an impact on family-based speaking practices. They also demonstrate the complex interplay between public and private histories in the development of linguistic ideologies and language as capital.