Dynamics of Tamil Finite System (DTFS) is the introductory part of the Historical Grammar of Tamil Syntax. DTFS examines Tamil finite system in its historical perspective. It maintains that the verbal constructions of ceyum, ceyuntu, cey(u)pu (>ceyyuu), and cey(u)ku types of early Tamil are identifiable as non-past impersonal finite constructions originally. It maintains that the early Dravidian finite system was impersonal in character without reference to person/gender appendage. The agreement markers are treated as the complementary variants of the personal pronouns. Although, the Dravidian syntax is of SOV type synchronically, it should have originated in OVS system with gender/person markers representing original pronominal subject NPs. The syntax of negation and certain relative clause constructions that have gone out of use are brought to notice. Such complementizers as an, in, am, um and their variants attested in Tamil are treated as the alternants of Be verb which in course of time is considered to have lost their lexical meaning.