How did suffixes express grammatical relationships in Proto-Dravidian?

In Proto-Dravidian, grammatical relationships at the word level were expressed primarily through suffixation. Words were formed by attaching suffixes to monosyllabic roots, which always occupied the initial position as the language utilized no prefixes or infixes.1

Roots could be extended by one or two suffixes to denote specific meanings, such as tense, voice, or case. For instance, suffixes were used to distinguish between intransitive and transitive voice, though in some later languages, these distinctions were lost, and the suffixes functioned as mere formatives or augments.12

Regarding the nominal system, nouns were inflected for case—such as the accusative, dative, and possibly the locative—by adding markers to an oblique stem. This oblique stem itself was formed by adding a suffix (or a zero suffix) to the noun. While the nominative case was not represented by any suffix, other grammatical roles were clearly defined through this process of adding specific markers to the root or stem. This reliance on adding distinct morphemes to a base is a hallmark of agglutination, a process where each element typically represents a single grammatical category.34