There are two ways to use a knife and fork to cut and eat your food, either in the European style or the American style. Either style is considered appropriate as long as you don’t change horses in midstream.
European Style
In the European style you cut your meat by holding your knife in your right hand, and the fork in your left hand with the fork tines piercing the food to secure it on the plate. The fork remains in your left hand with the tines facing down. Pick up the cut pieces of food with your fork and place them into your mouth.
American style
In the American style, you cut the food by holding the knife in the right hand and the fork in the left hand with the fork tines piercing the food to secure it on the plate. Cut a few bite-size pieces of food, then lay your knife across the top edge of your plate with the sharp edge of the blade facing in.
Change your fork from your left to your right hand to eat, fork tines facing up. (If you are left-handed, keep your fork in your left hand, tines facing up.)