This article examines the evolution of the adverbial phraseen efecto(in truth) and of the adverbefectivamente(truly), which while originating from a common semantic base, have followed different evolutionary processes. Eventually, they have come to share a common function as discursive markers to indicate a confirmation of the discursive message or a reinforcement of an assertion.Our goal is to describe the evolution of the acquisition process for the discursive value of these forms. We also analyze whether these changes are the results of a grammaticalization process and we describe the impact of discursive traditions in the incorporation of certain values. Finally, we show how this evolution is influenced by the paradigm changes caused by the incorporation, elimination or modification of the various lexical units in these forms through out the different stages in their development.