You don't say which machine it is. If it turns but doesn't spin then it could be a blocked drain pump if there is water in the drum at the end of the cycle.
If it doesn't spin with no water in the drum , then it's either it's either brushes ( carbons) , a control board or a broken wire to the motor.
Clean the armature with either meths or the finest emery cloth. stretch the springs and wire attached to the carbons and try the motor without the belt. The carbons may spark and if the motor goes into spin mode then replace the carbons stating the machine model number. Better still . take the carbons with you to the nearest washing machine spares shop in the yellow / golden pages.
Maximo
July 2008