Skou, a language of the central north coast of New Guinea, presents a rare example of multiple exponence of features in the agreement paradigms for subject. While this is a challenge for theories of morphology, because each morphological realization presents exactly the same featural information in Skou, there is a simple historical explanation for the modern complexities, involving cycles of cliticization. After the initial impetus toward developing an agreement system, the subsequent cycles were probably inspired by the progressive loss of differentiation in the inflected verb form due to sound changes in the language that simplified clusters and collapsed contrasts. This account allows us to understand many of the irregularities in Skou agreement.