Traditionally, language functions either are associated with the workings of the brain or defined in the realm of human interaction. In the first case, comprehension, speech production, the ability to read, spell, write, and similar are investigated. Through non-invasive methods, neuropsychologists attempt to establish how memory and language functions relate to the brain. In the second case, the focus is on social and communicative functions, with an increasing interest in underlying aspects (often computationally modeled). My approach is different in that it bases language functions in the practical experience, i.e., pragmatics, of the species. Language functions are, in the final analysis, sign processes. Preceding language, signs functioned based on their ontogenetic condition. As marks left behind-footprints, blood from an open wound, teethmarks-signs facilitated associations only to the extent that individuals directly experienced their coming into being. Cognitive awareness of such marks led to associations of patterns, such as action and reaction, cause and effect. Biting that leaves behind teethmarks is an example. Pointers to objects-broken branches along a path, obsidian flakes where stones had been processed, ashes where a fire had burned-and, even more so, symptoms-strength or weakness-are less immediate, but still free of intentionality. Imitation brought the unintentional phase of sign experience to an end. In imitative signs, which are supposed to resemble whatever they stand for, the mark is not left, but produced with the express desire to share. The function best describing signs that are marks of the originator is expression. Communication is the function of bringing individuals together through shared experiences. Signification corresponds to an experience that has signs as its object and relies on the symbolic level. It is the function of endowing signs with the memory of their constitution in practical experiences. Signification expresses the self-reflective dimension of signs. Expression and communication, moreover signification, vary dramatically from one pragmatic framework to another.