I have a Holmes pedestal fan that does this every few years. I have had this fan for about 10 years.
Unplug the fan and remove the fan blade guard. The fan blade should spin easily when you tap the edge of the fan blades with your finger. If the blade barely moves and abruptly stops, the bearings are dirty and need to be cleaned and oiled with 10W non-detergent motor oil. A quick-fix is a tiny bit of WD-40 where the motor shaft (the rod that the fan blade is mounted on) meets the bearing (the part of the motor that the shaft spins on). To properly fix this, you must oil both the front and back motor bearings which requires removal of the motor housing.
If the fan blade spins easily and you are certain that the fan is getting power (try a different outlet) the motor may be bad. Likewise, if the fan blade will not move at all. I do not know if Holmes sells motors for these fans. Here is their online support website:
Good luck from Detroit, MI.
P.S.: Never turn a motor-operated appliance on for more than a second if you know it's not working. That will cook the motor windings.