In Quechua-dominant Spanish interlanguage in the Andean region the gerund is frequently found instead of finite verb forms typical of monolingual Spanish. Using data collected among Quichua-Spanish bilinguals in northern Ecuador, this study challenges claims that direct transfer of the Quichua subordinator-s(h)pa— often called a “gerund” — is the immediate source of the Andean Spanish gerund. Quichua-dominant bilinguals produce Spanish gerunds mostly in subordinate clauses, reflecting the general pattern of Quechua. However, in a Quichua-to-Spanish translation task,-shpawas most frequently translated as a gerund by school children who had received Quichua language classes, and least frequently by traditional Quichua-dominant speakers. An examination of historical documents suggests that the gerund was used in Spanish foreigner talk directed at indigenous speakers. The ultimate source of the-s(h)pa=Spanish gerundequation is traced to 16th and 17th century Quechua grammars written in the Latinate tradition, and to Spanish priests’ and missionaries’ (mis)appropriation of this grammatical interpretation in their interaction with indigenous speakers in the Andean zone.