need more detail, how did this happen, do you have play in the shifter, can you feel gears being selected, in "neutral" if you slowly let off the clutch and press the gas do you move. - only with the car on, if doesnt really tell much when its off.
you may be missing the "bushing" at the bottom of the shifter itself. its a plastic piece that clips onto the small ball at the bottom of the shifter, if it brakes or whatever, (happened in a 240) you get tons of play and think youre in gears that youre not.