thematic roles

PART I
INTRODUCTION

Language learners need various kinds of strategies for interpreting what they hear or read, and for interpreting contextual text clues, which can provide them with information about the likely content of the language to which they are being exposed. Just as important, are strategies for determining and interpreting the grammatical units and relations that make up what they hear and read.
An English sentence is made up of units that combine to contribute to an overall semantic interpretation. Each unit of the sentence bears a grammatical relation to some other unit or combination. Noun phrases and sometimes clauses can bear a subject or object relation within the larger structure. These Noun phrases (NP) and clauses (C) also function as arguments of their predicate, and their semantic roles, roles such as “doer” are essentially semantic relation within the larger language structure.
These two types of relations, grammatical relation and semantic roles, we will explore this lack of correspondence between grammatical relation and semantic roles.
First a revision of terminology : because the term semantic role suggests a semantic concept broader than the set of roles assigned to arguments, we instead use the term thematic role, the term used in most technical discussions.




















PART II
EXPLANATIONS

A. THEMATIC ROLES
Thematic roles (in Chomskyan linguistics) is any of a set of semantic roles that a noun phrase may have in relation to a verb, for example agent, patient, location, source, or goal. Also called theta role
Thematic roles are classified as subtypes of Participant, which is further subdivided by two pairs of distinctions: determinant or immanent and source or product. That subdivision generates the four basic types of participants shown in the graph of Figure 1.

Figure 1 Graph representation of the subtypes of Participant.
Every participant is an entity that plays some role in a process. The four-way subdivision shown in Figures 1 and 2 distinguishes the participants according to the kind of role they play. In natural languages, those distinctions are expressed by grammatical markers such as prepositions and case markers, which link the verbs that express the processes to the nouns that express the participants. In logic, those distinctions are expressed by relations or predicates that link the symbols that identify the processes to the symbols that identify the participants.
• A determinant participant determines the direction of the process, either from the beginning as the initiator or from the end as the goal.
• An immanent participant is present throughout the process, but does not actively control what happens.
• A source must be present at the beginning of the process, but need not participate throughout the process.
• A product must be present at the end of the process but need not participate throughout the process.
As an example, consider the sentence Sue sent the gift to Bob by Federal Express. The gift and Federal Express are immanent participants, since the gift (essence) and Federal Express (resource) are present from beginning to end. Sue and Bob, however, are determinant participants, since they determine the course of the process from the initiator (Sue) to the goal (Bob). Unlike the immanent participants, the determinant participants are involved primarily at the endpoints. If Sue happened to write the wrong address, the intended recipient, Bob, might not get involved at all.

As subtypes of Participant, the thematic roles occupy an intermediate level in the ontology. Figure 4 shows a path through the hierarchy from the top levels of the ontology to the subtypes of Participant represented in Figure 1. Each of the thematic roles in Figure 3 could then be arranged under the four subtypes of Participant: Initiator, Resource, Goal, and Essence. The incomplete lines in Figure 4 suggest other branches of the ontology that have been omitted in order to keep the diagram from being cluttered.
Figure 4: Placement of the thematic roles in the ontology
At the bottom of Figure 4 are sample branches of the ontology under Agent and Theme. Doer, for example, has a subtype Driver, which has more specific subtypes like BusDriver, TruckDriver, and TaxiDriver. In principle, any of the thematic roles could be subdivided further to show distinctions that might be significant in some culture or domain of interest.
Although the thematic roles represent a linguistically important class of ontological categories, their common supertype Participant is several levels beneath the more general category Role. Therefore, Role would include many types that are not directly associated with verbs. As an example, the role Driver in Figure 4 represents only a person who is actively driving a vehicle; that role would be incompatible with the role Pedestrian. The category LicensedDriver, however, includes people who are legally authorized to drive, whether or not they are, at the moment, driving. In New York City, licensed drivers probably spend more time as pedestrians than as actual drivers. As another example, a person might have a continuous period of employment as a chauffeur, but would not be an active driver continuously. Therefore, the type Chauffeur would be a subtype of Employee and LicensedDriver, but not a subtype of Driver.
B. Thematic Relations
The term Theta Role is often used interchangeably with the term thematic relations (particularly in mainstream generative grammar — for an exception see (Carnie 2006)). The reason for this is simple: theta roles typically reference thematic relations. In particular, theta roles are often referred to by the most prominent thematic relation in them. For example, a common theta role is the primary or external argument. Typically, although not always, this theta role maps to a noun phrase which bears an agent thematic relation. As such, the theta role is called the "agent" theta role. This often leads to confusion between the two notions. The two concepts, however, can be distinguished in a number of ways.
Thematic relations express the semantic relations that the entities denoted by the noun phrases bear towards the action or state denoted by the verb. By contrast, Theta roles are a syntactic notion about the number, type and placement of obligatory arguments. For instance, in the sentence Fergus ate the kibble, the fact that there are two arguments (Fergus and the kibble) and Fergus must be capable of volition and doing the action and the kibble must be something that can be eaten is a fact about theta roles (the number and type of the argument). The actual semantic type of the argument is described by the thematic relation.
Thematic relations concern the nature of the relationship between the meaning of the verb and the meaning of the noun. Theta roles are about the number of arguments that a verb requires (which is a purely syntactic notion). Theta roles are a syntactic relation that refers to the semantic thematic relations.
Thematic roles is often convenient to identify arguments of (Fregean) predicates in terms of the following thematic roles, which are illustrated below.
• agent
• instrument
• cause
• experiencer
• recipient
• path
• location
• measure
• theme
Agents are arguments that bring about a state of affairs. The line between agents, on the one hand, and instruments or causes, on the other, can be fuzzy, but agents are (or are perceived to be) conscious or sentient, in a way that instruments or causes aren't. Some examples are given in (1)-(3).
(1) a. Agent: The lions devoured the wildebeest.
b. The boys caught some fish.
(2) a. Instrument: This key opens the door to the main office.
b. They must have used indelible ink.
(3) a. Cause: Hurricane-force winds demolished much of the town.
b. An epidemic killed off all of the tomatoes.

Experiencers are arguments that undergo a sensory, cognitive, or emotional experience.
(4) a. Experiencer: The rhesus monkey had never seen snow before.
b. Many people fear snakes.

Recipients are arguments that receive something (whether good or bad) in a situation.
(5) a. Recipient: They gave the workers a raise.
b. He spared me his usual sob story.

Recipients can be the endpoints of paths.
(6) a. Path: I'd like to send this package to my sister.
(my sister = recipient)
b. Lucky raced across the lawn to the edge of the forest.

Locations are simply places; like recipients, they can serve as endpoints of paths. (Chapter 7 contains some discussion concerning the difference between recipients and locations).
(7) a. Location: We put the book on the shelf.
b. I'd like to send this package to France.
(to + France = path)

Measure or amount arguments express extension along some dimension (length, duration, cost, and so on).
(8) a. Measure: They rowed for three days.
b. The book costs ten dollars.

Finally, the thematic role of theme is something of a catch-all. According to one definition, 'theme' refers to an argument undergoing motion of some sort, including motion in a metaphorical sense, such as a change of state. As is usual in the syntactic literature, we will also use the term for arguments that are most 'affected' in a situation or for the content of an experience.
(9) a. Theme: The lions devoured the wildebeest.
b. This key opens the door to the main office.

Major thematic relations
Here is a list of the major thematic relations.
Agent : deliberately performs the action (e.g., Bill ate his soup quietly.).
Experiencer : the entity that receives sensory or emotional input (e.g. The smell of vilies filled Jennifer's nostrils. Susan heard the song. I ran.).
Theme : undergoes the action but does not change its state (e.g., We believe in many gods. I have two children. I put the book on the table. He gave the gun to the police officer.) (Sometimes used interchangeably with patient.)
Patient : undergoes the action and changes its state (e.g., The falling rocks crushed the car.). (Sometimes used interchangeably with theme.)
Instrument : used to carry out the action (e.g., Jamie cut the ribbon with a pair of scissors.).
Force : mindlessly performs the action (e.g., An avalanche destroyed the ancient temple.).
Location : where the action occurs (e.g., Johnny and Linda played carelessly in the park.).
Goal : where the action is directed towards (e.g.. He walked to school.).
Recipient : a special kind of goal associated with verbs expressing a change in ownership, possession. (E.g., I sent John the letter.)
Source or Origin: where the action originated (e.g.,. She walked away from him.).
Time : the time at which the action occurs (e.g., The rocket was launched yesterday.).
Beneficiary : the entity for whose benefit the action occurs (e.g.. I baked Reggie a cake.).
Manner : the way in which an action is carried out (e.g., With great urgency, Tabatha phoned 911.).
Purpose : the reason for which an action is performed (e.g., Tabatha phoned 911 right away in order to get some help.).
Cause : what caused the action to occur in the first place; not for what, rather because of what (e.g., Since Clyde was hungry, he ate the cake.).

C. SEMANTIC AND GRAMMATICAL RELATIONS
The process of understanding which does what to whom in a clause would then required three major steps:
1. Identifying the predicate and the argument slots required
2. Identifying the noun phrase or clause arguments filling the slots
3. Identifying the grammatical relations these arguments bear (e.g: subject or object) in order to identify their thematic role (e.g: “doer” “undergoer”)
In other words, the grammatical relations would correspondence directly to the thematic role, which would just be the semantic translation of the grammatical relations
Lady Macbeth painted her nails
Ahmed will carry the passport
The noun phrase before each verb is the grammatical subject. The noun phrase after each verb is the grammatical object.
From the semantic point of view, the subject (Lady Macbeth, Ahmed) refer to participants who do the action. While the grammatical object (her nails, the passport) refer to the entities that undergo the action. So, if the subject is always ”the doer” and the object is always “the undergoer” Learners of English would face a straightforward task. Since the grammatical relations would correspondence directly to thematic roles, to understand the thematic role of each argument in a sentence, the learner would just have to be able to pick out the subject and any object. The thematic role of each argument would then become obvious.
Such a strategy works well for a sizable for proportion of the clauses encountered especially those in which the main verb is one of physical action (bring, take, paint, destroy). The subject is the “doer”, the role we shall now refer to as agent, and the object is the “undergoer”, the role we shall refer to as theme. The theme is the entity to which the action happens.
In the next example
: “A bewildered young woman was about to push the red button”
This sentence is about a “doer”, an “undergoer” and the action undergone. A bewildered young woman has the agent role and the red button has theme role.

In the next example:
“Noel liked those colours”
There’s no agent in these sentence. Noel doesn’t do anything action and those color doesn’t undergo action. This is because verb like express psychological states rather than action. So the grammatical relation of subject doesn’t correspondence to the role agent. With such psychological predicates as like, the subject is assigned a role called the experiencer role, while the role the object is assigned is called the theme role.
An argument consisting of an embedded clause is also considered an inert entity ¬–it doesn’t do anything or feel anything.
An experiencer is an entity engaged in a mental process or state involving cognition (thinking, believing, knowing, understanding), perception (seeing, hearing, smelling) or emotion (liking, hating, fearing, being angry)
In the next example : noel (experiencer) liked those colors (theme)
For the psychological predicate, we could modify the strategy by replacing the agent role with the experiencer role. The first argument would be the experiencer, the second the theme.
Now, look at some examples with different psychological predicate:
The colors (theme) pleased noel (experiencer)
Differ from the earlier set in presenting the theme first and the experiencer second. The experience seems more like a reaction or an effect caused by the theme. The theme is now subject and the experience is now object.
For many psychological predicates, grammatical relations subject does not correspondence to the thematic role experiencer nor the object relation to the theme. English predicates that express mental experiences vary as to which thematic roles are assigned to which arguments.
The sentence must have a subject, a requirement for English known as the subject constrain. But English has to a way to make the sentence grammatical without our having to have the theme in subject position.
e.g : “it is important that you leave early”
the noun phrase subject is the pronoun it, which has no intrinsic meaning of its own and isn’t assigned a thematic role by the predicate important.
At this point, we should define more clearly what an arguments as follows : an argument of predicate is a noun phrase or clause that is required by that predicate (in the absence of contextual information) and to which the predicates assigns a thematic role.
The fact that a subject may lack a thematic roll and the variability of the role assigned to subject make it clear that grammatical relation do not correspondence on a one-to-one basis to thematic roles. Knowing the grammatical relation an argument noun phrase or clause bears doesn’t automatically men knowing its thematic role. We have seen already that predicates very considerably as to:
1. The number of arguments they require
2. The thematic roles assigned to the arguments
3. The grammatical relations of the arguments to which roles are assigned.

D. THEMATIC ROLE ASSIGNMENT
• Thematic role agent
The agent is a mind-possessor who acts, usually attentionally.
e.g : Emilie Bronte opened the drawer with that iron key.
The drawer was opened by Emilie Bronte
Emilie Bronte is the agent in this sentence, the agent is typically the subject. A useful test for the agent role is to see whether the noun phrase can follow the verb order with its original verb following it in its active infinitive form.
• Thematic role instrument
The instrument is the thing with which the action done. The argument that iron key is the instrument I these example:
Emily Bronte opened the drawer with that iron key. (1)
That iron key opens the drawer. (2)
Emily Bronte used that iron key to open the drawer. (3)
In the first example, the instrument that iron key is the object of the preposition with, in the second it is the subject of the sentence, and in the third, it is the object of the verb used.
• Thematic role theme
The broad definition of the role theme covers three somewhat different classes of theme. The first correspondence to a narrow definition. it is the role of the often inert entity, which is in a certain state or position or is changing its state or position.
The girders were rusting.
The ball rolled down the slope.
The second is the role assigned to clauses. As previously stated, clauses can be argument, and since clauses the expresses propositions, which don’t do anything and don’t undergo anything, like other themes, clauses are inert entities. Look at the theme arguments shown in boldface in these sentence:
For Charlotte to outdo Branwel would shock that community
Patrick believed that Emily had the greatest talent.
Chomsky’s knowledge of language distinguished the class of clauses which are arguments as arguments with their own special thematic role. He calls the role proposition.
The third class is that of affected mind-possessing entities. Because this class is not a class of inert entities and seems different in nature, the term patient is sometimes used instead of the broader term theme. Patients undergo the action or process specified by their predicates and are affected by it. The argument the Bengal tiger would be described as having the patient role in the following example:
A wealthy hunter killed the Bengal tiger
The Bengal tiger died
note that event under a narrower definition of theme as only a role of inert entities, the theme role can be assigned to a living thing if it is treated in the same way as an inert object, as uncle Toby is in this sentence:
they moved uncle Toby to the corridor
unlike the Bengal tiger, uncle Toby is in this context considered as being as inert as, say, an armchair or a potted plant.
The three classes of themes have much in common when compare to other roles. In an active voice sentence, the theme is typically the subject of the verb be or the direct object of the verb.
• Thematic role experiencer
the experiencer is the one who experiences a mental state or process such as thinking, knowing, believing, understanding, fearing, etc.
the trooper hoped for promotion
mountain is word inspired the young poet
in the first occupies the subject slot; the second is the occupies the object slot.
In an active voices sentence, the experiencer typically in subject.
• Thematic role source and goal
The term source is to the location from which from someone or something originates and
the term goal to the location that serves our should serve as the destination.
The roles are illustrated in these sentences:
The delegates from Mexico city (source) for Buenos Aires (goal)
The government (agent) took over a billion dollars (theme) from the poor (source)
Marley (theme) change from a heartless miser (source) into a philanthropist (goal)
In active voice sentence, the goal is typically the indirect object or the object of to. And the source is typically the object of from.
• Thematic role benefactive
The benefactive is the role of the individual for whose benefit some action is undertaken:
The chef baked Jessica a cherry pie
The benefactive noun phrase is often introduced with the preposition for.
The chef baked a cherry pie for Jessica.
In an active voice sentence, the benefactive is typically the indirect object or the object of for
• Thematic roles for nonargument noun phrase
Noun phrase which are not arguments of predicates also have thematic role. They have the thematic roles of location and time. Recall that goal was defined as the role assigned to someone receiving something; that is, the transfer of something or someone else is treated as a shift in the location of that thing. If you give something to someone, that receiver is the destination (or goal) to which the gift is directed. Once the give is located at that goal, the goal person is no longer a goal, but rather the person possesses the gift and function as a kind of location for the gift.
The time noun phrase for last year in the sentence, last year the government divide the huge estates among the peasant, doesn’t follow a preposition. Noun phrase with time thematic role can, and something must, appear without preposition. Examples are last year, there, then, here, Tuesday, a month ago, and next week. This characteristic is relic of an earlier form English in which time and location noun phrase were of ten marked by special case suffixes rather than preposition.

E. CORRELATION BETWEEN SEMANTIC AND GRAMMAR
The semantic unit we’ve been discussing are preposition, predicates, and argument. The argument bear thematic role assigned in them by their predicates. We have seen that there is not a one-to-one correspondence since the grammar and the semantics are quite different systems with their own unit and relations. Nevertheless, there are indeed some interesting correspondences, including the following:
1. Preposition in the semantics system are often expressed as clauses in the grammatical system.
2. Predicates are expressed as verbs, predicate adjective phrases, predicates noun phrases, or prepositional phrase.
3. Arguments are expressed as either noun phrases or clauses.
4. Thematic roles show a partial correlation with the grammatical relations.





F. DEEP AND SURFACE STRUCTURES
We have claimed that the theme role is assigned to the noun phrase or clause following the predicate. If at the point, the clause has no subject, the theme noun phrase is moved into subject position. But if the theme argument is a clause, it need not be shifted since the filler it can be inserted into subject position.
Note that we are thus considering sentence s at two stages or levels, one at which a predicate assigns the thematic role theme to the argument following it, and a second level of analysis at which either the theme argument has been moved into subject position or the filler it has been inserted. It is at this second level that we can identify which arguments end up as subject and which as object.
So, thematic role are assigned on the first level, and the final grammatical relations are established on the second level. Not all theoretical approaches distinguish level like this, but this approaches, pioneered by Noam Chomsky, has been very productive and influential one for the analysis human languages.
The level at which thematic role are assigned is called the deep structure, usually abbreviated as D-structure. At this level the verbs, predicate adjective phrase, predicate noun phrase, and preposition are assign thematic roles to noun phrase or clauses that occur right next to them.
The level at which grammatical relations are established for each clause is known as the surface structure or more commonly, S-structure. At this level, noun phrase like the filler it can occur without having to have any thematic role.
The two levels, D-structure and S-structure, are connected to each other by the kind moving operation, one moving the theme argument from the position after the predicate into the empty subject position. Such operations are called transformation. And they gave their name to an earlier version of Chomskyan syntax known as generative-transformational grammar.

PART III
SUMMARY AND REFERENCES

A. SUMMARY
1. Thematic roles (in Chomskyan linguistics) is any of a set of semantic roles that a noun phrase may have in relation to a verb, for example agent, patient, location, source, or goal
2. Thematic roles is often convenient to identify arguments of (Fregean) predicates in terms of the following thematic roles, Agent, instrument, cause, experiencer, recipient, path, location, measure, theme.
3. Thematic roles are classified as subtypes of Participant, which is further subdivided by two pairs of distinctions: determinant or immanent and source or product.
4. the grammatical relations would correspondence directly to the thematic role, which would just be the semantic translation of the grammatical relations
5. Preposition in the semantics system are often expressed as clauses in the grammatical system.
6. Predicates are expressed as verbs, predicate adjective phrases, predicates noun phrases, or prepositional phrase.
7. Arguments are expressed as either noun phrases or clauses.
8. Thematic roles show a partial correlation with the grammatical relations.
9. The level at which thematic role are assigned is called the deep structure, usually abbreviated as D-structure.
10. The level at which grammatical relations are established for each clause is known as the surface structure or more commonly, S-structure.


B. REFERENCES
1. Jacobs, Roderick A. English Syntax. Oxford university press. Oxford.
2. Wikipedia.com
3. Oxford dictionary