semantic role

A term used in SYNTAX and SEMANTICS to refer to the semantic relations that link a PREDICATE to its ARGUMENTS in the description of a situation. Thus in the sentence Roger milked the cow the entities are related by the action described by the verb: Roger as the volitional instigator is often termed the AGENT; and the cow as the affected entity, the PATIENT. There is no general agreement on the number of PARTICIPANT ROLES available to speakers of languages, but others include: INSTRUMENT, the means by which an action is performed or something comes about; THEME, the entity which is moved by an action, or whose location is described; EXPERIENCER, the entity which is aware of the action described by the predicate but which is not in control; BENEFICIARY, the entity for whose benefit the action was performed; location (LOCATIVE), the place in which something is situated or takes place; GOAL, the entity or place towards which something moves; and SOURCE, the entity or place from which something moves. It has been suggested that these roles may be subsumed into two main types: the macro-roles of actor and undergoer, or, in an alternative terminology, the proto-roles of agent and patient. These roles have been important in the establishment of semantic classes of verbs. Other names for these roles include deep semantic cases, functional roles, participant roles, and, especially in Chomskyan linguistics, thematic (or theta, θ) roles.