Semantic relations were introduced in generative grammar during the mid-1960s and early 1970s ([Fil68], [Jac72], [Gru67]) as a way of classifying the arguments of natural language predicates into a closed set of participant types which were thought to have a special status in grammar. A list of the most popular roles and the properties usually associated with them is given below.
A participant which the meaning of the verb specifies as doing or causing something, possibly intentionally. Examples: subjects of kill, eat, hit, smash, kick, watch.
a participant which the verb characterizes as having something happen to it, and as being affected by what happens to it. Examples: objects of kill, eat, smash but not those of watch, hear, love.
A participant who is characterized as aware of something. Examples: subject of love, object of annoy.
A participant which is characterized as changing its position or condition, or as being in a state or position. Examples: objects of give, hand, subjects of walk, die.
The thematic role associated with the NP expressing the location in a sentence with a verb of location. Examples: subjects of keep, own, retain, know, locative PPs.
Object from which motion proceeds. Examples: subjects of buy, promise, objects of deprive, free, cure.
Object to which motion proceeds. Examples: subject of receive, buy, dative objects of tell, give.