How do I know if it is the capacitor or the motor that isn't working?

Last night my tumble dryer overheated. The element was working but the drum wasn't turning.
Today,I took the lid off,I turned the dial to put it on and it is as if the motor is trying to run but the drum isn't moving,unless you give it a nudge,and doing so,the drum wll turn.
Could it be the capacitor or the motor?
Can you help me?