1. Steering Wheel Lock Your steering wheel may be locked. Try turning the wheel gently left and right while turning the key. This usually unlocks both the wheel and ignition. 2. Car Not in Park or Neutral In automatic cars, the ignition won't turn unless the gear is in "Park" or "Neutral." Make sure the shifter is fully engaged. 3. Worn or Damaged Key Keys wear out over time. Try using a spare key if you have one. If that works, your main key may need replacing. 4. Faulty Ignition Cylinder If the ignition cylinder is damaged, the key may not engage properly. This will require a mechanic or locksmith to repair or replace the cylinder.