The lord whose oracle is at Delphi neither reveals nor conceals but indicates. (Heraclitus, fr. 105(93) Many works have been devoted to Greek oracles, fewer ones to their language as a look at the bibliography will show. Therefore it is very interesting to address the oracular domain from a linguistic point of view. Though the texts of oracles kept in Greek literature cannot be taken as authentic testimonies, at least they give a view on how people had considered them in Antiquity, and their frequent occurrence in historiography and literature allows a linguistic analysis. The first feature that clearly appears is that the oracles do not speak by themselves: the oracle is for human beings a way of entering a conversation with the gods, who generally answer the questions posed through the seer's voice. Thus the form of the question draws stereotypical forms of answers. Most of the time, the question is not a general one, but a practical alternative, like "Must I do this or rather that?", be it for an individual or a collective person, a city suffering from plague or any calamity, for instance. The form of language met is thus a dialogue, and the catalogues of collected oracles resemble more or less the manuals for learning foreign languages that contain several types of questions and answers about quotidian life. The answers given by the god have been kept through local or familial traditions. They never give a clear-cut answer to the question asked, but seem to provide an enigma, speaking in metaphors and using poetical devices (periphrases or traditional formulas, for instance). As Heraclitus said, the god does not speak but sêmainei, which means to give signs (sêmata, σήματα). In the case of the Apollinian oracles, those "signs" are transcripted as words, be it by the Pythian priestess or by specialized interpreters, so that the god seems to speak the same Greek language as the consultants. The most archaic forms of signs may have been fortuitous events interpreted as sent by the gods: in Iliad 2.328-9 the drakôn killing and eating eight newborn birds and their mother means, as the seer Kalchas explains, that the Achaeans have to fight the Trojans during nine years, and the city will be taken within the tenth one; in the Odyssey 17.541-5, Telemakhos' sneeze is a sign, clear for the participants at the scene, and particularly for Penelope, that the vow expressed in the former verses will meet success. More usually however, people were seeking those signs through special activities (journeys to oracular sites, rituals of consultations etc.). Anyhow, the nature of the signs implies opacity, ambiguity: the sign is a transposition of meaning into another field than direct expression, and thus waits for an explanation, be it by a professional interpreter as Calchas or by any person interested in it, like Penelope. From a single quick dialogue the oracular moment may evolve to a durable conversation, for instance when the consultant does not understand the first answer of the god or does not obey his instructions. Thus in Herodotus, we meet several instances of linguistic exchanges for a more or less long period, until, for instance, the evil announced in the first answer eventually leads to the foretold loss for the miserable city or individual who misunderstood the veiled language of oracles: in book 5, Herodotus first uses indirect discourse for a suite of oracles touching the city of Corinth (5.79-80; the myths of Thebe and Aigina lead in 82 to building the statues of Damia and Auxesia), and then goes to direct discourse for the report of a first oracle given to Eetion (whose name means 'eagle') on Labda's pregnancy (5.92; her name also is significant, meaning 'lame'); this oracle is not taken into account, so that a second one is given to the Corinthians: we can note that the same words κύει "is pregnant" and τέξει "will give birth" occur in both of them: oracular language speaks more or less the same formulaic language as the epics, it uses the same kind of verse (hexameter).