SUMMARY
This article analyzes the distribution of the copulas ser and estar in Spanish, based on a scalar theoretical framework. The main proposal is that their distribution can be captured in terms of the scalar structure of the predicates involved and the presence of cognitive salient points on those scales. The proposed framework centers around ser predicates involving a single degree on the scale, while those with estar involve an interval, which additionally must involve an onset, or salient point. This analysis has two advantages. First, it accounts for subjects and closed-scale adjective pairs not being able to alternate between ser or estar. The endpoints present on closed-scales act as strong salient points that, based on the Principle of Interpretive Economy, require that the copula estar is used if it can. Second, this analysis also accounts for the distribution of estar with open-scale predicates and explains why adjectives like famoso ‘famous’ or rico ‘rich’ are virtually absent from estar predications, despite having the appropriate temporal reading. Cognitive salient points are also responsible for generating the appropriate scalar interval required for estar predications, although their being weaker than endpoints on closed-scales does not require estar be the only copula available. The article also accounts for the nature of these onsets on open-scale adjectives and provides a diagnostic tool to determine which adjectives have them, and consequently can appear in estar predications.