Cognitive and generative approaches to linguistics have taken a different perspective on grammatical polysemy and grammaticalization. While the former see polysemy as a core characteristic of language and a necessary result of grammaticalization within idiolects, the latter see it as a less interesting phenomenon peripheral to linguistics proper. Grammaticalization is seen as a phenomenon of language acquisition which does not disturb the homogeneity of idiolects. These differing perspectives have generated much debate between the two approaches and are even in large part responsible for the different programmatic focuses of each. While the disagreement over grammatical polysemy between these two approaches to language is rooted in entrenched commitments on each side that are perhaps irreconcilable, at least some common ground does seem to be possible. Specifically, when it comes to intergenerational corpora, it seems that both cognitive and generative approaches to linguistics can agree that the universal phenomenon of grammaticalization would result in polysemy at least at the language community level. This can serve as a common ground on which both generative and cognitive linguists can join efforts in describing and explaining usage profiles of grammatically polysemous forms at the corpus level according to prototypicality, even if disagreement persists on the nature of the idiolect.