the passanger side windshield wiper works but the drivers side wiper does not.

2 things; 1-At the end of the wiper arm going into car,there's a cap that lifts up and there's a nut you can tighten.The cap looks like part of the wiper arm. 2-If the nut is tight,the linkage bushing might of came off. They call it a wiper transmission arm on most vehicles.