This article attempts to provide conclusive evidence to decide on the existence or absence of passive in two Native American languages, namely Lakhota and Cheyenne, which exhibit a similar behaviour in this respect. Given that it is evident that these two languages do not show examples of an English-style passive, that is, considering the concept of “passive” from the viewpoint of traditional grammar, it will be necessary to study this issue from a different angle, presented in this case by the Role and Reference Grammar (hereafter RRG) (Van Valin and LaPolla, 1997). Thanks to its marked typological orientation, this theoretical framework makes it possible to see both the similarities and differences between these languages, as well as to s...