Folk theories of language and culture are informal beliefs and assumptions about languages, language users, and cultures, and language users. Whilst previous studies in sociolinguistics (e.g. Preston, 1993) and applied linguistics (e.g., Wilton & Stegu, 2011) have attempted to understand the nature and significance of folk knowledge and attitudes, recent shifts towards concepts such as language ideologies have somewhat diluted the interest in folk linguistics. In this talk, I seek to redirect attention to the overlooked, ‘dark’ side of ordinariness of folk theories that reflects and sustains hierarchies and inequalities in languages and human relationships. Drawing on my lived experiences in China and in the UK with linguistic and cultural hierarchies, I illustrate the omnipresence of folk views and the forces shaping and sustaining these views. I then reflect on how folk knowledge has been navigated in my research about family language policy and practice and potential avenues for further exploration. I argue that we need to take folk theories, particularly those related to hierarchies, seriously, due to their profound impact on ordinary, everyday linguistic practices and social inequality.