What could be wrong if a Ford Expedition will not go into gear?

Automatic? Torque converter no longer pumping fluid Valve body blockage Shift linkage broke? Manual? Shift linkage broke? Shift fork broke or bent Gear breakage? throwout bearing not working? Here are some ideas................................ ON MINE, IT WAS THE PIVOT PIN AT THE BASE OF THE SHIFT LEVER HAD MOVED OR SLIPPED OUT OF POSITION. I JUST HAD TO TAP IT BACK INTO POSITION.