- In our dualistic approach, the soul is one that possesses the knowledge of a/the language (not clear to me if all souls speak Hebrew or just 70, like the angels or just any language)
- AFAIC, the soul comes from God readymade, not "baby-soul" or "soul-cell", unlike the body that develops.
- Once a newborn is out and breathing (or say, during the first year) he should be able to speak as an adult because the soul does not need to learn to speak and he has all the organs needed.
- Maybe the soul does not know how to control the tongue and the vocal cords, but once the baby figures out she should be talking like an adult.
- Maybe the Tora-teaching angel slaps too hard that the fetus forgets language, but I'm not aware of the gentile practice of learning and slapping.
- Maybe some souls are fresh-new "baby-souls", but ARIZ"l proposed that nowadays there are no "new" souls coming down but only "recycled" ones (second-hand or grown-up, so to say).
Of course, the question might be extrapolated to other intellectual or spiritual activities, but I currently focus on speech. So, why do we need to learn a language??