At this age, your child is fully ready for some ground rules, the ones which will help him become a better human being later in life, and also embed kindness and humbleness in his personality. Every parent wants their child to learn the basic rules in life that would create a good human being.
What you need to know
If you see your child behaving in a rude manner with you or other people then BEWARE! It is high time you must work on inculcating the morals of kindness within the kid. Before your child enters the social arena or any other gathering where they interact with children of their age, it is necessary for them to be humble and kind.
Training should start at home
You can start this training at home by imparting knowledge verbally about how we should help others. Teach them to greet people with a smile and how to talk softly. Ask all the members of the family to follow these points in order to make the child observe and learn quickly. The act of sharing is very important for a child to learn about the humble aspects of human nature. Ask them to share their food with friends, which would act as a stepping stone to becoming a good person in future.