Semantic roles provide a way to relate participants in situations to the situations themselves. Semantic roles originate from early work in lexical semantics and propose a finite set of underlying categories that unite semantic and syntactic levels. Semantic roles can be identified semantically, pointing to intuitive natural classes based on how events and states are conceptualized, and syntactically, showing covert grammatical distinctions in how nominals behave. Semantic roles are inherently relational and label the relations of arguments to predicates, having no existence outside of predicates. Each argument of a verb is assigned only one semantic role.

1. Sematic Roles

2. Definition
Semantic roles provide one way of relating situations to their
participants.
Also known as: Semantic case, thematic role, theta role, (deep) case
roll, and participant role.
• Semantic roles originate from the early work connected with
lexical semantics.
Fillmore (1968), postulates a finite set of underlying categories which serve to
unite semantic and syntactic levels.
“It is case which is an ‘underlying syntactic-semantic
relationship’” – Fillmore(1968:20)
Cases can be Identified both semantically and syntactically

3. Syntactic identification showing covert grammatical distinctions
in the ways in which nominals behave in the syntax (deals with
subject, predicate, object, complement and adverbial).
Semantic identification pointing to intuitive natural classes
based on the way in which we conceptualize states and events
(deals with meaning).

4. The Nature of Semantic Roles
• Semantic roles defined as relations, functions, and sets of
entailments or properties.
• Semantic roles are inherently relational notions; they label
relations of arguments to predicators and therefore have no
existence independent of predicators [Rappaport & Levin,
1988:17]

5. Semantic Roles Uniqueness
• Only one participant in a situation bears a given role
• Every argument of every verb is assigned only one semantic
role

6. Semantic Roles
No Terms and Meaning Sentence Examples
1
2
3
4
5
6
7
8
Actors= performs some action
without affecting any other entity
Affected= undergoes changes due to
some events/affected by some other
entity
Affecting= without any actions,
affects another entity
Agent= by its actions affects any
other entities
Associate= tells the status/identity of
another argument
Effect= comes into existence through
the action of the predicate
Place= names of the location where
actions of the predicate occurs
Theme= a topic of the predicate that
doesn’t express action
Sylvia left.
A window broke; Tom broke a
window.
Betty likes opera; Opera delights
Betty
Tom broke window.
Roger is a student.
Tillie baked a pie.
The fireman climbed a ladder.
Audrey is a computer expert.

7. Verb Valency
• The valence of a lexical items is its inherent relationality that
allows it to govern a particular number of arguments.
• Valence pattern (also known as argument structure, predicate frame,
and government pattern): the configuration of arguments that are
governed by a particular lexical item.