Floyd, S. (2011). Re-discovering the Quechua adjective. Linguistic Typology,15, 25-63. doi:10.1515/LITY.2011.003.
This article describes the adjective class in Quechua, countering many previous accounts of the language as a linguistic type with no adjective/noun distinction. It applies a set of common crosslinguistic criteria for distinguishing adjectives to data from several dialects of Ecuadorian Highland Quechua (EHQ), analyzing examples from a natural speech audio/video corpus, speaker
intuitions of grammaticality, and controlled elicitation exercises. It is concluded that by virtually any standard Quechua shows clear evidence for a distinct class of attributive noun modifiers, and that in the future Quechua should
not be considered a “flexible” noun/adjective language for the purposes of crosslinguistic comparison.