Q) How well-mannered and attentive can a 3-year-old be? My husband and I are in continual conflict over his behavior, what is acceptable and how we can make him learn control and concern for others.

My husband says I've been too lenient, letting him explore everything that isn't fragile or dangerous and that I don't make him practice good table manners. He says our son will pay for this later with severe, negative reactions when he's away from home, so he often enforces his expectations with harsh admonitions and spankings.

I am permissive and try to avoid battles of will unless they're needed for his protection. I also feel that manners and behavior are largely taught by example and patient instruction, rather than demands.

I have enrolled him in some group programs and taken him to library story hour but he won't participate or sit quietly. He seems too immature to enjoy structured activities or to be still for 30 minutes.

In September he'll start a nursery school that has an unstructured play program with a few group activities. He's very active and happiest when he can run and play freely.

I want him to be with other children and have a variety of experiences because he has few playmates and because we've gone through major changes this year, including a new baby and a move to a new community.

How can we control our son's inappropriate behavior without being punitive? When will he be attentive and well-mannered? How can I deal with my husband on this issue?

A)You can expect your 3-year-old to be well-mannered and attentive when he's about 17. Most of the time.

A 3-year-old is usually attentive for a maximum of 10-15 minutes and is just learning what table manners are all about.

Your son may have more problems than most 3-year-olds because he is by nature an active little boy and because he's getting such mixed messages at home.

You and your husband are each following your normal temperaments, which is fine, but you each seem to be compensating for the other. He gives too much discipline to make up for your permissiveness, and you may be making up for his demanding ways by being too free.

This is unwise. Parents don't have to agree on each aspect of child care, and most of them don't. You'll get along better if you defer to your husband on some occasions, and he defers to you on others. A child can easily accept one set of requirements from the mother and another set from the father, according to who's in charge, just as he can accept different rules at school or at the homes of his friends.

He can't, however, handle phony acceptance -- where a parent grits her teeth and says, "That's okay, sweetie. I know you were just expressing yourself when you threw the centerpiece" -- nor can he handle repeated criticism. When a child gets too many "no's," he starts giving them back. This is how he becomes negative.

Harsh punishments and spankings are unkind -- and they don't work. The child eventually rebels and then the punishments, and the rebellion, escalate. If this continues, he's out of control by adolescence and then both parents will turn permissive because they can't do anything else.

The child who's reared permissively will rebel, because he wants and needs reasonable limits and he will act wilder and wilder until he gets them. His exasperated parents finally become complete authoritarians.

Moderation, of course, is a key to good discipline.

Firm limits, as broad as you can stand them, work best, with praise and encouragement given for the things he does right. When a child is praised for sitting still for five minutes one night he'll be more likely to sit still for six minutes the next.

Other encouragement is more subtle. The freedom to explore makes a child independent, and respect and courtesy teach him good manners.

You also need lower expectations.

Your son can sit at the dinner table for 15-20 minutes, but he'll also squirm, spill and prattle.

Your husband will bear this better if the two of you eat alone at a later hour three to four times a week, after the boy has gone to bed, and if you picnic in the park and eat fried chicken with your fingers another night.

This leaves two to three family meals together, which will go better if you have your son toss the salad with dressing or help you layer the lasagna. By investing in the occasion, he'll tend to live up to the honor, especially if he's allowed to pass or serve the dish he helped to make -- and gets all the credit for it.

Your child also will act better if you eat by candlelight, because it's enchanting, and you'll think he acts better because you won't notice him as much.

To understand your son better, read How to Stop the Battle With Your Child, by Don Fleming with Linda Balahoutis (Prentice Hall; $9.95).

To understand yourselves better, consider the stress a new baby and a new neighborhood has put on your husband and yourself.

It's time to praise and encourage each other. Questions may be sent to P.O. Box 15310, Washington, D.C. 20003.