Stories, whether in film or in literature, generally follow an arc. Things happen to a character or characters that we judge and like or dislike according to their personalities and their choices; situations develop, conversations take place, a certain point is reached, and there is a conclusion. In an Asghar Farhadi film (winner of an Academy Award for Best Foreign Film for “A Separation,”) only the conversation part is certain. In his new film, “Le Passé,” (“The Past”) shown in competition at the Cannes Film Festival, people talk, not hearing each other—as when they talk through a glass pane in an airport—or hearing wrong, or hearing too much.