We've been teaching Noah to say "please" and "thank you" for some time now. While he knows that's what's expected and kind, he rarely says either without prompting.
Here's a rather humorous encounter from the other day, in my husband's words. Obviously, we still have some work to do. :)
Daddy kindly gives Noah an animal cracker.
Noah takes the cracker with a gleeful "Oooh!" and stuffs it in his mouth.
Daddy then asks Noah the all-familiar: "And what do you say to Daddy?"
*There is no answer at first as Noah is happily crunching his cracker.
Daddy waits, and then asks his son again, "What do you say?"
Noah gives a puzzled look in reply and then swallows.
Daddy cups his ear so his son knows he's waiting to hear from him and repeats the question a final time:
"What ... do you say ... to Daddy?"
Noah puts his hand over his ear (like a phone) and says, "Hello, Daddy!"