In this work a series of examples are collected and analyzed to hypothesize the incidence of the prepositions in the modality of the speech, property that have never been considered in the study of these particles. In this manner a review of a series of oppositions between the prepositions de/por (of/for), con/de (with/of), en/con (in or upon/with); the use of prepositions in exclamatory sentences, and the contrast between the prepositions in the locative construction, empirically demonstrates that in such contexts one of the prepositions clearly present evidence of subjectivity, which refers back to the issuer.