Childhood paradoxes

My son is shy. Not the quiet-withdrawal type of shy, the glare-you-in-the-face-and-refuse-to-budge type of shy. At home, however, we can't stop him from talking. He chats about everything.
He's beginning to talk about events that happened in the past, like, "Mummy, member me, Mummy, Nanny, Pa, Daddy, Essie went zoo?" He's also very observant about his surroundings. One of the reasons his meals take at least an hour and a half to complete is that he talks so much between mouthfuls. This evening I took him down to the supermarket with me, and he talked incessantly - until we ran into someone we knew. After we said goodbye, the non-stop verbiage commenced again with "Who's that somebody?"

The problem, I've discovered, is that I've taught him how to speak improperly. For him, everything is a question. Unknowingly, as he grew into speech, I would say "What colour is that flower?" instead of saying "That's a red flower." My reasoning at the time was that I wanted to know how much he knew, and wanted to get him to produce a response. Now it's come back to bite me. Rather than announcing his own observations, he interrogates: "Who's that somebody there?" or "What's that?", waiting for me to give a response before he tells me. I find myself now having to help him unlearn ways of speech so that he can learn them properly. His speech patterns frustrated me until the penny dropped that it was a problem partly of my own making - though he does have an inquisitive nature!

Mind you, his current favourite phrase is "I know..." followed by a suggestion for play. There is hope yet...