It sounds as though you do indeed have a gifted child, and keeping up with him will be an exciting challenge. You are wise to be concerned about overstimulating him, something that many parents seldom consider. But since you are aware that this can happen, I doubt that it will be a problem for you.
I am sure you have heard of Montessori Schools. The founder of the movement, Maria Montessori, wrote a great deal about something that applies to your guidance of your son. She identified what she called “the problem of the match”—that is, matching the level of stimulation provided by parents and teachers to the level of development and interest shown by the child. If the teaching is too far above where the child is, he will tune you out; if it is too low or just where he is at the moment, he will be bored or uninterested. You need to find things that are just a little bit beyond where he is and help him move to that level. If, in all areas of his development, you find the appropriate match—not too much, not too little—you won’t need to worry about overstimulating him.
Certainly you want to encourage his interest in books. Read to him faithfully, letting him point to pictures in the text. Resist the temptation to try to teach him to read (as it may turn him off), but, if he points to a word and asks what it is, don’t hesitate to tell him. And, since he likes crayons, think of other art media that he can use. Finger painting is very appealing to young children, as is clay. Try to interest him in toys that help improve fine motor skills and develop eye-hand coordination. And limit his TV time. At his age, being active and actually doing something is very important. Talk to him both in specific conversations and as you do your work. And sing to him and help him learn little songs in both languages.
Most of all, enjoy him and love him. If at some point in the future he seems to “slow down,” don’t be unduly concerned. Many children develop in alternating spurts and slumps, and he may also show this pattern. If you have another child, he may appear to “level off” and cause you to worry that he isn’t getting enough attention. If you remain as good an observer as you now appear to be, you will know how to correct your own behavior to match his needs.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.