Reference: the linguistic essential.
Three chimpanzees learned to label three edibles as "foods" and three inedibles as "tools". Two chimpanzees could then similarly categorize numerous objects during blind trial 1 tests when shown only objects' names. The language-like skills of the chimpanzee who failed (Lana) illustrates that apes can use symbols in ways that emulate human usage without comprehending their representational function.
D000819:Animal Communication; D000818:Animals; D001244:Association; D007858:Learning; D008037:Linguistics; D002679:Pan troglodytes / Q000502:physiology*