Believe it or not, there is a magic number for teaching manners.
"Generally speaking four years old is a great time to start teaching these lessons," de Muyshondt says. At that age, kids' brains are able to comprehend commands and certain concepts, making it easier for manners to stick. That being said, it doesn't hurt to role model good manners teach them please and thank you early on.
Source: Flickr user theloushe