Não há resposta específica. Suposição e especulações puras só são possíveis. Aqui estão algumas das perguntas da FAQ do IMDB :
"I'm not saying it'll be easy...but go to that man and tell him the truth. Okay?"
"I HAVE TO BE LEAVING... BUT, I WON'T LET THAT COME BETWEEN US... OK?"
Alternatively it could also be "I love you. Don't forget to always tell the truth... OK".....
The director made it the way it should be - for each person to fill in what they feel was said. But it sounds like, "I love you deeply. When John gets back, tell him the truth. Okay?" This fits with the rest of the film in that she asked him for advice about marriage, and he was telling her not to make the same mistakes he had
Or: "Can I say something? Go to that man and tell him the truth. Okay?"
maybe this: "Sometimes you have to go halfway around the world to come full circle."