Tamil verb stems may be inclusive of a voice morpheme that encodes the degree of agency of the verb. Hence, using Paramasivam's (1979) terminology, these kinds of verbs are paired verbs of which one is the affective and the other its effective counterpart. In the former, the action expressed by the verb is realised by an agent and affects a patient, whereas in the latter the consequences of the action fall on the subject who realises the action. This paper intends to analyse how missionaries described the verb system of Tamil which differed substantially from their own model of reference (Latin and Portuguese), and how they understood paired verbs, as defined above. As such, taking into account the Western sources that missionaries used to compose and organise their descriptions, this paper focuses on both verb conjugations and paired verbs in Tamil. It also demonstrates how the Latin grammatical framework was applied for the description of Tamil verbs and discusses the Indian grammatical sources available to missionaries. Given that the present classification of Tamil verbs is based on the one offered by a missionary, Karl Friedrich Leberecht Graul (1814-1864), this study highlights how earlier missionaries' descriptions contributed to the current classification.