The distinction between judgments of perception and judgments of experience has been a source of consternation to many commentators, since Kant’s claim that only judgments of experience involve the application of the categories seems to run afoul of the central doctrine of judgment found in the first Critique, where Kant proposes that all judgments are categorial. This chapter casts the distinction in a new light, by focusing not on whether all judgments must be categorial, but rather on what processes guide the transformation of judgments of perceptions into judgments of experience. Drawing on a comparison Kant makes between the categories and grammatical principles, the essay suggests that the way that categories apply to perceptual content mirrors how grammatical rules structure linguistic content, and that this allows for a new understanding of the role that judgments of experience play in the Prolegomena, and Kant’s critical idealism more broadly.