Common semantic roles

Role	Description	Typical Grammatical Realization	Example
Agent	The doer of the action	Usually subject in active voice; “by + NP” in passive	The chef cooked the meal → Agent = the chef
Patient	The entity undergoing a change	Direct object (active) or subject (passive)	The cake was eaten → Patient = the cake
Theme	The entity the action is about or acts upon, may or may not change	Object, subject, or PP complement	She dreamed of flying → Theme = flying
Experiencer	Entity perceiving, feeling, or experiencing	Subject or object of psychological verbs/adjectives	She is aware of the problem → Experiencer = she
Beneficiary / Recipient	Entity receiving or benefiting from the action	Indirect object, PP	She baked a cake for her friend → Beneficiary = her friend
Instrument	Tool used to perform the action	PP (usually with with/by)	He opened the door with a key → Instrument = key
Location / Locative	Place where action occurs	PP, adverbial	She waited at the station → Location = station
Temporal	Time when action occurs	PP, adverbial	He left in the morning → Temporal = morning
Cause / Reason	Why the action occurs	PP, adverbial	He trembled because of fear → Cause = fear
Purpose / Goal	Intended outcome of action	PP, adverbial	He studies for the exam → Goal = exam
Source / Origin	Origin or starting point	PP, adverbial	The news came from the newspaper → Source = newspaper