This paper has its starting point in the search for the causes of the very frequent presence of a possible monovalent predicate (fio) in the Peregrinatio Egeriae. The use of fio to present the development of repeated actions, often rituals, justifies its frequency -especially in the second part of the work -and, more specifically, the almost exclusive use of its passive factivity meaning. This fact is intrinsically linked to the use of the lexical or morphological passive to carry out this presentation of facts that usually constitute an entirely new piece of information from a pragmatic perspective, something that implies a determined order of constituents and the activation of an inversion mechanism, so that the majority sequence turns out to be Verb--S(ubject). This reality is corroborated by the study of the behaviour of predicates with similar characteristics and functionality. Among other related reasons, the selection of the passive -which has a pragmatic motivation and which is triggered as a textual cohesion device -to present the verbal process from the point of view of the event itself is revealed as one of the most explanatory causes of the concrete reality present in the text under investigation.