The car starts, but when I put it in gear, the car does not move.
If the shifter linkage has failed or broke it will not allow the transmission to be put into gear. The transmission has multiple clutch packs that control the different gears that are used while driving. Inside these clutch packs are steel discs and clutch discs. As the clutch discs wear down, the clutch material breaks down and begins floating around in the fluid. If the fluid is not regularly serviced, too much of the material can be worn off and trapped in the fluid. The transmission may still work even if most of the material has worn off because it is mixed in with the fluid. If this fluid is changed, all of the clutch material is removed from the transmission and the transmission will slip sometimes to the point of complete failure. A proper inspection should be carried out by a qualified technician in order to pinpoint the reason why your car is not moving.