Q: "I am encountering problems of a 'single parent.' I use quotes, for I am single in the sense of never having been married.

"I find that I am not alone in this segment of single parenthood and feel our numbers will increase. The 'baby boom babies' are growing older and we want more out of life, even if we must get it in unorthodox ways.

"I am 33, professional, and living several hundred miles away from my family. While I have their emotional support, there is no role model for my child to follow.

"How do I tell him about the differences in our family and the traditional family? He is only 5 1/2 months, but has recently discovered the sound 'dada' and there is no one to respond to it positively.

"He is going to a nursery, where I overheard children playing the other day. One small boy was the husband. Where there is no husband, how do I present such a concept? Where will the role model come from? And how do I explain that his father has chosen to ignore the reality of my son? There has been no contact between him and me since early in pregnancy.

"And then there is the working mother factor.

"Recently there was an article in The Post about the need for stability during the first five years of childhood; that if the mother stays home, the children are less prone to social problems, drug problems, mental problems. I want to know how to avoid them.

"The negative attitudes are hard to ignore. I have enough questions without reading about the certainty of failure. It is difficult to maintain a positive attitude when hit from all sides by negative, so-called authorities. a

"There are so many of us who need to know that our undertaking can be successful. Parents Without Partners only seems concerned with parents who are divorced, separated, or widowed."

A. Families come in almost as many shapes and sizes as people, and in each one the child reflects the attitude of the parent, and not the books of the experts.

Actually, your problems are the same as any other single parent who gets no child support (and most do not) and no shared custody (which many wish they didn't have). You're like a widow who should have gotten a divorce.

It will be a long time before your child realizes that his father ignores him, unless it continues to matter to you. It shouldn't. You've made a strong, fine choice to bear your child and rear him, but you don't have the right to make that choice for his father. And even it you did, would you want your child to be influenced by a parent who puts pleasure so far above responsibility?

You worry about "dada," but "dada" and "mama" and "nana" are some of the first sounds a baby makes. When there is no daddy, you should interpret the sound to be something else, like doggie, the way you might turn nana into banana if there were no grandma around.

As for the concept of husband, forget it. Divorce is so rampant; the child of the '80s will think single parents are much more normal than you do unless you make an issue of it.

Your child will, however, need a role model -- a male who is going to be kind and loving and masculine -- and you have to provide one just as you would if you were widowed, divorced or married to a workaholic.

It may mean adopting a neighborhood grandfather to visit once or twice a week; hiring a college student to babysit on a regular basis; having your first grader join a soccer team -- if it has an enthusiastic male coach -- or the Scouts later. You also can ask your friends if your child can be part of some father-son adventures, in exchange for some giving on your part. It's up to you to extend your family if your own is not big enough.

How do you explain all this to your child? Bit by bit. And when he asks, you'll say, "No, you're right. We don't have a daddy in our house." And that's all you'll say unless he asks more.

Later it will be, "No, honey, I don't know where he is," without ever saying that he "chose to ignore" the child's reality. Some things are better left unsaid.

He may be ready to know the truth when he is in early grade school -- and when he is, he will ask -- but it will be a few years more before he should get a heavy discussion about it. This won't be perfect, but neither are divorce, or widowhood, and an awful lot of marriages.

And will this news hurt him? Not much. And will your career cause terrible problems? Only if you let it. There will be a great deal of stability in your home if you accept the responsibility of your job and your child without a lot of resentment.

It will be much easier, however, if you get yourself some support.

Parents Without Partners may not be for everybody, but its founder, Carol Vejvoda Murdock, has written a fine book: Single Parents Are People Too! (Butterick, $9.95). Another good one is The Working Mother's Complete Handbook by Gloria Norris and Jo Ann Miller (E. P. Dutton, $7.95). Although neither book treats the single, working parent who has never married as a separate problem, both discuss the dilemmas of working parents and single ones and their advice is sound.

And then there is psychotherapy. Your child will do much better if you find some respective psychologist or psychiatric social worker who will let you sound off your anguish, your anger and your fears for a while, so you won't have enough left to pass on to your child. County mental health clinics are generally quite good, and sliding fee scales are customary.

If you try to bottle your anxieties, you'll only end up giving them away.