Verbs and nouns convey different types of motion in event descriptions*

This paper reviews the evidence for Kersten’s (1998a) theory of a division of labor between nouns and relational terms in the description of a motion event. According to this theory, nouns tend to convey intrinsic motion, or motion defined with respect to a frame of reference internal to the object carrying it out. Relational terms, on the other hand, tend to convey different types of motion from those conveyed by nouns. The prototypical relational term conveys extrinsic motion, or motion defined with respect to an external frame of reference. Even when verbs do convey intrinsic motion, the motions conveyed by such verbs are more general and abstract than the motions conveyed by nouns. Three lines of research provide support for this theory. The first demonstrates that word learners associate novel nouns with intrinsic motions and that they associate novel verbs with extrinsic motions. The second demonstrates that even when nouns and verbs are both associated with intrinsic motion, the way this motion is represented is different in the two cases. Finally, the third line of research provides evidence regarding the development of the division of labor, suggesting that it stems from a bias to associate novel words with novel referents.