Language Acquisition

"I can walk up to someone I don't know and I can make a sequence of noises that I've never made before by pushing air through my mouth. I will take a thought in my head and make it go into their head."

The parents simplified their language then as the boy's language developed they mirrored it and used more complex ones.

By the time a child is five they'll know as many as 5,000 words. As they grow up they'll learn 3000 every year. As adults they'll be speaking 15,000 words every day.

We're the only specie that can convey complex meaning and thought. No other animal has ever developed speech.

Not even our closest relatives the chimps can talk, psychologists spent nearly seven years trying to teach one, Vicky, to talk but failed.

Theory behind why we can talk: our unique anatomy
Our voice box is low in our throat so our vocal tracks are longer. For animals it's high in the throat.
This has been disproved though as they're capable of lowering and reconfiger the vocal track like a human. So that isn't the constraint, it must be in the brain.

The left part of the brain is for language, the front part is for speaking and the back is for understanding speech.

Front is associated with word retrieval.

A baby responds to the mothers voice over anyone else's, the only explanation for this is that they've been listening to her whilst in the womb.

"The forbidden experiment"
The only way to find out if language is fully innate is to leave a child to grow up on their own in a silent isolated room. Would they be able to develop language this way? No one will ever know because the study is way too cruel.
A way of getting around this is by using birds: they copy their parents sing just like we predict children copy their parents. They isolated male birds from their fathers, and their song developed to no more than a croak.

Oxana had an innate concept for language even though raised by dogs. However for her first three years she had lived in a domestic setting so this isn't fully reliable.