The paper proposes a novel theory of the categorization of acts and applies it to the semantics of action verbs, with fundamental consequences for semantic theory and beyond. The theory is based on Goldman’s (Theory of human action. Princeton University Press, Princeton, NJ, 1970) multilevel theory of action which is taken here as a theory of categorization. Goldman’s central notion is level-generation: acts of a type may under circumstances generate acts of other, more abstract types. The acts form a hierarchical structure which Goldman calls an act-tree. Level-generation results in a conceptual relation called c-constitution here, i.e. constitution under the given circumstances; I also introduce the more general term cascade for act-trees. In the second part, multilevel cascade-structure categorization is combined with a cognitive semantics that models meanings with Barsalou frames. A multilevel analysis of the concept of writing is discussed in depth and detail in order to illustrate the potential and the consequences of a cascade approach to verb semantics. It is shown that the concept of c-constitution can be generalized as to cover the roles of persons and objects across levels in a cascade. The generalization suggests that multilevel categorization may be a very general and fundamental phenomenon in the psychology of categorization.