In linguistics, the grammatical patient, also called the target or undergoer, is a semantic role representing the participant of a situation upon whom an action is carried out,[1] or the thematic relation such a participant has with an action.
In Japanese, for instance, the patient is typically affixed with the particle o (hiragana を) when used with active transitive verbs, and the particle ga (hiragana が) when used with inactive intransitive verbs or adjectives.
Although Modern English does not mark grammatical role on the noun (it uses word order), patienthood is represented irregularly in other ways; for instance, with the morphemes "-en", "-ed", or "-ee", as in eaten, used, or payee.
[clarification needed] The grammatical patient is often confused with the direct object.
The patient is a semantic property, defined in terms of the meaning of a phrase; but the direct object is a syntactic property, defined in terms of the phrase's role in the structure of a sentence.