Your son sounds EXACTLY like mine. If I didn't know better, I would think that I had written this post myself. The interest in counting, colors, shapes, languages are IDENTICAL to my 4 y.o.
If your son is indeed gifted, then he will STILL be gifted when he gets to kindergarten and grade school. Don't rush academics on him, just let him play and work on his social skills with other children his age.
Continue to read to him at home and expose him to things he shows an interest in but don't fall into the trap of making every book and game about what he likes only. He needs to be able to relate to other children and show an interest in the things they like too.
We enrolled my son in a Montessori last year (3 full days per week) and it was a disaster. I think the day was too long for him and he was/is a little delayed socially and a outlier. That combined with the fact that he knows a lot about the Universe and numbers made the school label him autistic right off the bat.
My husband and I, not being from large families or having much experience with other children, took their assessment to heart thinking "well they've seen hundreds of 3 year olds so they must know what they're talking about."
We had him evaluated several times and each time were told that the school was way off and had no business diagnosing the child. This of course was a relief but it put us through an emotional roller coaster for months. We were making ourselves crazy over evaluating every little thing he did.
My son, like yours, is really shy and better at dealing with people one-on-one as opposed to groups. He can be a slow warmer and needed a more structure environment in a smaller group setting. His old preschool (yeah, we dumped them!) had 19-23 kids for 2 adults.
I was lucky enough to find a small home preschool (run by a family therapist) with a focus on getting kids ready for school socially over academically. That said, they are flexible enough that they will work on special subjects with a child if the child starts showing signs of boredom.
I know that this was the best thing for my kid, and since he sounds SO much like your boy, I had to share.
Best of luck!
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