Hi and welcome to FidYa, I am Kelly,
If it does not agitate or spin suspect the lid switch. Listen for a microswitch click as the lid just opens or closes. No Click = bad lid switch.
If it spins then the lid switch is fine and there is a problem with the water level control pressure switch or possibly the control.
Since you did not include a model number this is my best guess for a 3.2 cu ft machine
MVWC300VW0
This lid switch is item 6 this link:
http://www.appliancepartspros.com/partsearch/model.aspx?model_id=5519632
The water level control switch is item 4 this link:
http://www.appliancepartspros.com/partsearch/model.aspx?model_id=5519632&diagram_id=28626536#d28626536
The timer item 7 of the above link can also cause this symptom. You must elimiate the water level control as a possible cause first. There is a FOLDED wiring diagram in the literature packet insde the top panel 3 x 5 envelope you can use to jumper the wires on the water level control switch. If the motor agitates then the water level switch is the problem. If it does not agitate it can be the timer or the motor. (More troubleshooting required via the wiring diagrams following power through the circuit to the motor.)
At this time I think you may just have a water level control switch problem. If you do end up replacing it... the wash tub must be empty or it will overflow when testing.
Thanks for choosing FixYa,
Kelly