Teaching children to eat takes a lot of patience. First they have to be familiarized with the food, then with cutlery and then using a spoon and a fork. At first they will be clumsy, spreading food everywhere, but they will gradually learn. You will need to show them how to do it.
Children can eat on their own by around the age of three, chewing with their mouths closed and staying seated until they finish eating (although they will get up between courses). It is quite a challenge for them, but remember to start slowly.
From the age of one they will start acquiring the necessary skills, although every child is different. Don't pressure them and give them time. Only when the child shows interest should you take advantage and start teaching.
In the beginning, most children like exploring food with their hands, particularly if they are hungry or tired. Using cutlery is very difficult for them, as this requires fine motor skills. To make things easier, leave a spoon within their reach at mealtimes from the age of 10 or 11 months so they can start exploring how to use it. They will be able to lift it to their mouths and suck on it but won't know how to hold food on it. Eat with your child whenever you can (or at least sit your child at the table while the older ones eat): naturally your child will play at imitating you.
From around 18 months your child will start using the spoon. It will be a disaster at first, with food staining everything and more being dropped on the table and floor than going into the mouth. Some advice? Look for a spoon that is small (one that fits easily into the mouth) and flat (one that doesn't pick up too much food).
From the age of two, your child will know how to use the spoon properly and can start on the fork. You now need to explain which foods should be eaten with the fork and which with the spoon. Above all, stay patient and remember that this is one more challenge in your child's growth process.