Q.Our 3-year-old son -- bright, imaginative and articulate -- has an 8-month-old brother and a large extended family and is a leader at his preschool. Despite his engaging personality, however, he can be very shy at times, usually around adults.

At his 3-year checkup, he refused to answer the doctor's simple questions, such as "How old are you?" and "Can you tell me your last name?" His lips were sealed through the entire visit. And yet I had talked with him about the doctor visit beforehand and had role-played a bit to prepare him.

He also refuses to talk with any new people he meets and he won't even interact with adults he knows well, like his aunts and uncles, unless he has had time to warm up to them first.

At this point I try not to answer the questions for him, and sometimes I say to the other person, "I'm sorry. I guess he doesn't feel like talking right now." But sometimes I'm embarrassed when my son turns away, rolls his eyes or walks off. He doesn't act scared or even shy, he just acts rude, as though the adult is not worthy of his attention.

I've tried to teach my son proper manners, by telling him what it means to be polite and how to answer certain questions, such as "How are you today?" because I think he doesn't know what to say sometimes. Even though he gets it, his behavior stays the same.

Is this typical 3-year-old behavior? Will he outgrow it? And is there anything more I can do to help him?

A.Be patient. Accept the boy as he is. He sometimes has the shys, because -- as you suspect -- he simply doesn't know how to act.

Your little boy was born knowing how to suck, to sleep, to cry and to wet, but it will take him many years to learn how to be polite all the time.

In the meantime, sympathize with him. Tell him that it must be hard to talk with people who are so big, so strong, so full of words and questions. He needs to know that you understand.

You should also understand this basic truth: Children want to be good. They want to have nice manners. And they want to do these things because they want to be liked. There's just one problem. They don't always know how to express their feelings in a socially acceptable way. At 3 they get embarrassed, make a face and run away, and at 4 or 5 they call a favorite aunt or uncle "Poo-poo head" or whatever hilarious name they've learned at school.

Don't be embarrassed by these shenanigans. Instead, take advantage of your son's ability to imitate others -- especially his parents. If you keep guiding him with gentle examples and role-playing games, he'll learn to speak politely and for himself. Until then, you can answer for him, but first ask him if he wants you to do that, or if he wants to answer the question himself. Sometimes he will; sometimes he won't.

You also should tell him that good manners are another way of being kind. Therefore you expect him to smile when he says hello, to show that he's happy to see someone, and in a few years, you'll expect him to stand when a grown-up comes into the room, to make her feel welcome; to give her his chair so that she might sit there; to eat neatly at the table so she won't be offended by his table manners; and to open the door for her when she leaves, so she will know that he was glad she came. Teaching your son about these niceties, and the reasons for them, will be more effective than telling him to behave, again and again. Once he knows what to do, he will begin to be more comfortable -- and more polite -- with adults.

Good, amusing books for children will help too, particularly "Manners" by Aliki (Morrow; $5.99) and "What Do You Do, Dear?" by Sesyle Joslin (HarperCollins; $6.95) and at 6, another witty book by Joslin, "What Do You Say, Dear?" (HarperCollins; $5.95). Humor is one of the best ways to teach your child anything as long as he doesn't think that you're making fun of him.

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