Case Marking and Argument Roles in Spoken Sinhala

In linguistic typology, the relationship between the grammatical arguments of a verbtypically labeled S (the single argument of an intransitive verb), A (the agent of a transitive verb), and O (the patient/object of a transitive verb)is central to understanding a language's case-marking system. Spoken Sinhala exhibits a nuanced pattern that deviates from strict nominative-accusative or ergative-absolutive alignments, primarily due to the role of animacy and definiteness.

Defining S, A, and O

To analyze Sinhala, we first categorize the arguments:

• S (Intransitive Subject): The sole participant in an intransitive clause (e.g., "The child sleeps").
• A (Transitive Agent): The active participant in a transitive clause (e.g., "The child eats the apple").
• O (Transitive Patient): The affected participant in a transitive clause (e.g., "The child eats the apple").

The Core Case Marking Strategy

In spoken Sinhala, case marking is not applied uniformly to all nouns. Instead, it is highly sensitive to the animacy and definiteness of the referent. This is often referred to as Differential Object Marking (DOM).

The Agent (A) and Intransitive Subject (S)

In the vast majority of standard declarative sentences, both A and S appear in the direct case (unmarked/nominative form). Whether the noun is human, animal, or inanimate, the subject of a transitive verb and the subject of an intransitive verb typically share the same morphological form.

The Object (O)

The marking of O is where Sinhala displays its most distinct behavior. Spoken Sinhala utilizes an accusative marker (commonly -va for animate nouns and -ai or zero marking for inanimate nouns) based on specific criteria:

Referent Type	Marking
Animate, Definite	Accusative (-va)
Inanimate, Definite	Zero marking or Accusative (-ai)
Indefinite	Zero marking

Animacy and Morphological Complexity

The "Animacy Hierarchy" dictates that human beings are more likely to be marked in the object position than inanimate objects. If an object is human, spoken Sinhala almost obligatorily attaches the accusative suffix -va. For example, "I saw the boy" becomes mama kolla-va dkka. If the object is inanimate, the speaker has more flexibility, often leaving it unmarked unless emphasis or specificity is required.

Syntactic Implications

Because A and S are generally unmarked (nominative), while O is subject to differential marking, Sinhala is classified as a Nominative-Accusative language in its basic structure. However, the reliance on animacy means that the "accusative" case is not a default for all objects, but rather a functional tool to distinguish a specific, sentient patient from the agent.

Summary of Argument Relations

The relationship in Sinhala can be summarized as follows:

• S and A alignment: They behave identically in the direct case, forming a nominative pivot.
• O marking: O is distinguished from A and S through the use of the -va suffix (for animates) or discourse-based marking (for inanimates).

This system highlights that in spoken Sinhala, the grammatical role of a noun is determined not just by its position in the sentence (typically SOV order), but by the interaction between its semantic role and its animacy. This makes the language an excellent example of how pragmatic concerns, such as the need to disambiguate agents from patients, shape the evolution of case-marking morphology.