I have a 2 yr old, an almost 4 yr old and an almost 6 yr old – all boys. They all have pretty good manners, but I am always encouraging consistency. There are a couple of books that we all (kids & adults) love that have also reinforced they what & why of manners for kids…”Time To Say Please” by Mo Willems (the guy who wrote “Knuffle Bunny” and many other great books) and “Do Unto Otters” by Laurie Keller (who wrote “Scrambled States of America” – another favorite). Also, my two oldest boys are taking karate now which also reinforces respect & manners. Karate might be too young for your child – Jake was 3.5 when he started and he’s just now getting the hang of it. The right preschool can really help too – for some reason kids seem to listen better when it’s not their parents teaching them! 🙂 Good luck & kudos for making the effort!