Your child is now slowly learning to differentiate between right and wrong. They would have learnt a few things by following parents, teachers and other elders around them. This is the age to teach them to refine the manners they have already been taught at 6-7 years and adding on to them.
Your child would have already learnt to say “Good Morning”, “Good Night”, “Hello” “Sorry” and “Thank you,” etc. But if they are not following them yet then it is the right time that you insist on these manners now. Other manners that you can start teaching them are being polite, table manners, phone etiquette. Polite parents will have polite kids. When you are polite, the kids learn by your ways. Let them know how good manners help them in getting better responses from others. When they show politeness without prompting, acknowledge the act.
What you need to do
Teach table manners – washing hands before having meals, eating / drinking with open mouths, to eat without complaints and decline politely when the kid does not like what is being served, excuse themselves before leaving the table. Show them that having these manners are appreciated when in outside company.
If your child has a chance to talk on the phone when you are not there, let them know how to answer it and how to take a message. They are still not able to write down the message from the caller, but definitely should be able to ask who the caller is, who the message is for and whether they can take the number to ask you to call back.