Boundary Glottals and A'ingae Information Structure: A Morphological Argument for a Discourse Feature Geometry

I describe and analyze a pattern of morphosyntactically conditioned realization of the glottal stop -ʔ in A’ingae (or Cofán, an endangered Amazonian isolate, ISO 639-3: con). The glottal stop -ʔ appears before three information structural morphemes—the new topic -ta NEW, contrastive topic -ja CNTR, and exclusive focus -yi EXCL—when they attach directly to a TP, but not when they attach to other categories, such as DPs, CPs, or adverbs. I propose that the glottal stop (-ʔ) is a spell-out of T° conditioned by linear adjacency to a higher-order discourse feature [δ] (Bossi and Diercks, 2019; Mikkelsen, 2015) that dominates all the maximal information structural features in a feature geometry. By documenting an overt realization of a vocabulary item conditioned by [δ], I provide novel morphological evidence for a hierarchical arrangement of discourse features (Bossi and Diercks, 2019; Mikkelsen, 2015), and of Ā-feature geometry more broadly (e.g. Aravind, 2018; Baclawski, 2019; Baier, 2018).