Dear Mr. Dad: For the past few months my son, who is almost four, has been going through the “why” phase—constantly asking questions like, “Why is sky blue?” and “Why can’t dogs sing?” Most of the time I don’t know what to tell him or how to make him stop. Any advice?

A: I’m sure just about every parent who’s reading this is nodding his or her head. This phenomenon is so common that you could safely add it to the short list of life’s guarantees—right after death and taxes and probably just before the sun rising every morning. So my first suggestion is to stop trying to make your son ask fewer questions. Judging from his age and the questions you quoted, your son doesn’t seem exceptionally or unusually inquisitive.

Starting at about three, children really start to focus on the world around them and try to explore every little bit of it. Plus, he’s now much more able to actually understand what’s going on. He’s fascinated by the things work and can’t get enough of cause and effect. At the same time, his language skills are blossoming. Combine that insatiable curiosity with an exploding vocabulary, and you’ve got a never-ending and sometimes annoying stream of questions.

But what your son doesn’t have right now, is the capacity to tell the difference between questions that are reasonable and those that aren’t. Come to think of it, that’s a distinction that eludes many adults too. So when the dog barks instead of singing, your son wants to know why. Frankly, I do too.

A lot of animals are born prewired with the ability to walk, slither, hop, eat, hide, and more. But humans aren’t. Yes, we’re born with some basic reflexes, but for they generally disappear within a few months. From there on, we’ve got to learn everything from scratch, one step at a time. And as exhausting as it is for you, that’s exactly what your little boy is doing.

So how should you handle all these questions? To start with, don’t ignore them. The good news is that most questions four-year-olds ask aren’t exactly rocket science. Give the best, most complete—and, of course, age appropriate—answer you can (if, for example, your son asks where he came from, “Chicago” could be a better answer than a lengthy explanation of the birds and bees).

If you don’t know an answer, it’s perfectly fine to say so. But don’t just leave it at that. Suggest some ways that you and he could discover the answer together. Go to the library and check out some books that might provide the information you need. He’s too young for Internet searches, but that’ll be coming sooner than you think. Or go to the zoo, the museum, the grocery store, or the nearest Ferrari dealer.

When you listen carefully to your child’s questions and you patiently answer them (or help him find the answers), you’re doing two very important things. First, you’re nurturing his sense of curiosity, which is a critical step in the learning process. Science, literature, and just about everything else couldn’t exist if people hadn’t been curious enough to ask, “Gee, I wonder what would happen if I….” Second, you’re laying the foundation for good and open communication between the two of you. And, as he gets older, knowing that you take his questions seriously will be proof that he can turn to you with any problems. Whether he actually does that is a different story. But at least, deep down inside, he’ll know.