This paper describes the syntactic-discursive behavior of the pronoun me in two epistolary materials from two different regions of Northeastern Brazil: Sertão of Pernambuco and Recôncavo in Bahia. Theoretically, this article is based on the Functionalism theories in linguistics, namely: Hopper and Thompson (1980), Neves (2012), Fuzer and Cabral (2014), and Halliday and Matthiessen (2014). It is also supported by the Valence Theory Grammar, which is approached according to: Neves (2000), Welker (2005), Perini (2007), and Rodrigues (2007). As part of its research methodology, the following steps were carried out: the selection of the contexts in which the phenomenon appears in the corpora, the collection of the socio-historical data regarding the missivists', the grammatical classification of the pronoun me, and the analysis of the verbal valence, accordingly with the assumptions of Functionalism. As a result of the analysis of the functionalities of the clitic me, it was observed that traditional grammars and descriptive grammars do not cover the particularities of the ethical dative pronoun, as they do not mention its capacity to be a discursive particle, a zero-switchable element in the sentence structure, not an actant, but in the communicative context it positions the writer and it can be associated with matters of morality and affection.