Just like a plain edge knife, a serrated knife will eventually get dull when you use it. However with the right tools, you can restore a serrated knife to its original sharpness. Here's how.
Set up your sharpening tool and follow the directions for the particular model you are using.
Work the hone, which should be perpendicular to the cutting edge of the knife, in a back-and-forth motion. Apply firm pressure.
Stop occasionally to feel the backside of the blade for a raised burr.
Move onto the next serrated tooth section when you feel or see the raised burr.
Complete this process until the ground side of the knife is completely ground. Turn the knife over.
Grind the burrs off the knife with a light grind of the hone. Do not sharpen the backside of the knife.