I find it amazing that if a child is brought up in a community/country different from the origin of the child, the child is still able to pick up and speak their language fluently. Our ability, as humans, to imitate and communicate is incredibly complex regardless of where we are from.

So my question is, is there a language that cannot be spoken like this? One which only people with a certain genetic advantage can speak fluently during upbringing.

Of course anyone can learn a language by putting effort into it. My question is only for one learnt during upbringing (native language).

(Not sure why my responses are downvoted. I’m a non-native English speaker. Sorry if I didn’t communicate something properly. It’s just a scientific curiosity.)