A notion developed in cognitive grammar. Relates to the relative prominence of participants in a linguistically encoded scene and reflects the more general perceptual phenomenon of figure-ground organization. Ronald Langacker argues that the grammatical functions subject and object are reflections of trajector-landmark organization.

Langacker calls the semantic pole of the symbolic assembly that fulfils the subject function the trajector, which reflects the observation that the prototypical subject is dynamic. The semantic pole of the symbolic assembly that fulfils the object function is called the landmark. This reflects the observation that the prototypical object is stationary or inert, as evidenced by an example such as the following: The car passed the garage.