This paper provides the first detailed documentation of aspectual properties of motion verbs in Blackfoot (an Algonquian language) from the Kainaa dialect. In particular, the focus of the paper is to detail how a sentient subject in this language is associated with an inherent endpoint of motion events (i.e., delimitedness). I show that in Blackfoot, an event can have a delimited construal when a sentient subject is an agent (but not a theme). A language-specific requirement for event delimitedness is thus the presence of an external argument that is sentient, which I formalize as a feature [m(ental state)] on a DP, as in Ritter (2015). A major contribution of the current study is thus to show that event delimitedness can be constrained by formal features of the external argument, whereas previously only the internal argument was thought to be involved in event delimitedness.
