This paper presents a novel analysis of the Persian formant am-/an- in a broad context in order to clarify its diachrony, synchrony, etymology, and gloss. The formant is classified into two types: those derived from Old Iranian ham-/han- “together,” and those belonging to the cognitive process. These formants always convey four metaphoric cognitive percepts: collection/collocation, multiplicity, pluralism and infiltration. These percepts are manifested in three forms: receptacle; cluster, multiplicity, doubling; and, to a lesser degree, permeation. The study also explores the presence of some cross-language regularities in neighboring languages with the same cognitive concept of am-/an-, which conforms to the categories and classifications proposed by this paper.