Please and Thank You

We are trying to teach Ethan manners, it is a very long and tedious process considering he doesn't understand very well. But we're starting at the beginning, please and thank you. We just say please whenever he's grunting for something, give it to him and then say thank you. Occasionally he'll repeat "p." One of his favorite things to do is play in the garage with his daddy. Tonight, after Daddy got home later than usual (adding to the fact that Ethan didn't nap too well and was very tired), Ethan goes squealing to the garage door. I told him not tonight, it's late, cold and time for a bath. He starts crying and going "p" "p" like he was trying to say "please." So sweet, Daddy had to take him in the garage for a few minutes.