Learn how to keep a knife sharp with this video. Just follow a few steps. When your knife is not sharp it poses some problems so follow the steps.
First step is sharpening the knife with sharp-rod.
Second step is sharpening the knife with sharpening stone.
Third step is sharpening the knife with electronic knife sharpener but it's very expensive. Just adjust the knife between the rods of the electronic knife sharpener; then apply the machine you can get the sharpened the knife. So just follow the steps to avoid the problems with knife.