You cannot use a dimmer switch on a fan motor but you can find fan speed controllers.
Can you put a ceiling fan on a dimmer switch.
In this circumstance the light kit could be connected to a dimmer switch and the fan motor connected to a toggle switch.
By all means you can connect a ceiling fan directly to a dimmer switch but you may run into problems along the way.
A dimmer switch as the name suggests lets you control the intensity of the light produced from the light to which it is connected such as a ceiling fan with a built in lighting fixture.
The new switch does require an additional electrical wire.
The wall dimmer switch reduces power flow and interferes with the fan control.
You can install a ceiling fan light dual dimmer switch to operate the fan speed and light intensity from the original wall switch location.
You may need an electrician for this.
An example of this is that the motor in your fan could be damaged and rendered useless.