In this article, I propose a novel way to distinguish between agreement and clitic doubling . The innovation lies in examining what happens when the relation between the relevant agreement morphology and the full noun phrase fails to obtain: whether the agreement morpheme still shows up, bearing default φ-features, or disappears altogether. The workings of the proposed diagnostic are demonstrated using a family of constructions in “substandard” Basque (Etxepare 2006). Besides supporting the proposed diagnostic, the analysis of Basque provides a new perspective on the typological status of the Basque agreement system, as well as evidence against the traditional analysis of unergatives in Basque as being underlyingly transitive.