Thematic role

A thematic role or semantic role is a way in which an object can relate to an event.

Some examples of thematic roles are:

• “agent”: who is willfully causing this event?
• “instrument”: what is used to carry out this event?
• “patient”: who or what is affected/changed by this event?

Syntactic and thematic roles

Thematic roles exist in contrast to syntactic roles, like “subject” or “direct object”: these describe a way in which something participates in a verb at the syntax level.

In Toaq, syntactic roles are the ones already represented by the “blanks” in verb definitions:

choıdea: ___ stabs ___.

Whereas thematic roles are represented using verbs that relate an event to an object, generally used as prepositions ():

chou: ___ is an event with ___ as its instrument.

An example

In the two sentences below, the syntactic subject and object are exchanged, but the thematic roles stay the same: Brutus, the agent, is causing change, while Caesar, the patient, suffers this change.

Sentence	Syntactic roles		Thematic roles
	Subject	Object	Agent	Patient
(1) Chỏıdea mí Bủtusy mí Kảısary da. Brutus stabs Caesar.	Brutus	Caesar	Brutus	Caesar
(2) Mủ chỏıdea mí Kảısary mí Bủtusy da. Caesar is-stabbed-by Brutus.	Caesar	Brutus	Brutus	Caesar

Note that the assignment of Agent and Patient roles to Brutus and Caesar happens “automatically” according to the semantics of choıdea. To stab is for an agent to stab a patient.

We can further dress the event up with an “instrument” using a thematic role word:

(3) Chỏıdea mí Bủtusy mí Kảısary chòu sa tỏemy da.
(4) Mủ chỏıdea mí Kảısary mí Bủtusy chòu sa tỏemy da.

We say that the stabbing-event, or the being-stabbed-event, “happens using” a knife.

Table of thematic role words

Each of these has a definition like: “___ is an event with ___ as its (Role).”

Toaq word	Role	Example
chou	Instrument	chòu sa tỏemy, “using a knife”
nhe	Extent	lỏq náo nhè sáqheı kẻıcıu, “the water is 30°C hot”
Words below this line are unofficial
sıy	Starting point, source, origin	jảra nháo sìy búe, “they run from the house”
fay	End point, direction, goal	jảra nháo fày búe, “they run toward the house”
puoq	Purpose	pùoq jâı súq, “so that you may be happy”
gekyı	Stimulus	ảchu jí gèkyı hóegıo, “I sneeze from the sunlight”
juqkyı	Recipient, benefactor	sủaq jí jùqkyı súq, “I sing for you”
toıkyı	Agent	pỏaq núoqmy tòıkyı jí, “the mirror shatters by my doing”
tekyı	Patient	rủqshua tètyı jí, “it rains on (affecting, i.e. wetting) me”
taqkyı	Agent + patient (affecting self)
lıekyı	Experiencer

“Agent” and “patient” roles are usually baked into a transitive verb, so translating toıkyı and tekyı can be a bit tricky or ambiguous.