What is nominalization? Towards the theoretical foundations of nominalization

過而不改、是謂過矣 (孔子) This paper discusses foundational issues in nominalization, focusing on empirical, conceptual, and theoretical problems that have plagued the field for years. Current definitions of nominalization are based on narrow observations on verbal-based nominalizations, while languages across the globe display nominal-based ones, many of which share morphology with the former. Nominalization morphology in many languages also applies to units larger than words, yielding grammatical nominalizations besides lexical nominalizations. The imbalance in the past studies, which have focused on so-called relative clauses at the expense of grammatical nominalizations, has resulted in a lopsided view on the relationship between the two. This, in turn, has led to the mishandling of different manifestations of nominalizations as if they are derivatives of relative clauses, as suggested by the widely used terms such as “headless relative clause” and “internally-headed relative clause”. We demonstrate that these, including the ordinary restrictive relative clause, are not independent grammatical structures but are epiphenomena arising from the uses of grammatical nominalizations. A clear distinction between structures and their use is a theoretical prerequisite in arriving at a satisfactory understanding of the nature of grammatical nominalizations and their role in grammar.