what does bill murray whisper in lost in translation

The final scene of Lost in Translation features Bill Murrays character, Bob Harris, whispering something in Scarlett Johansson's character, Charlotte's, ear. The exact words of the whisper have been a subject of much speculation and debate. According to the final draft of the script, Bob tries to tell Charlotte he loves her but he can't muster the words. It was planned that Bill Murray would improvise the ending line as he wished. Director Sofia Coppola maintains that Bill Murray's final line to Scarlett Johansson was unscripted and that no one, including her, knows what Bill Murray said except for Murray and Scarlett Johansson. While the exact words of the whisper remain a mystery, the ambiguity of the scene is part of its mystique and has contributed to the film's enduring popularity.