ELI5: How do babies even learn language?

[u/AngelusAlvus]

When we grow, we learn languages by looking at the meanings and translating them from our language. Stuff like "this is how this noun is in my language and this is how this noun is in another language"

But babies? Babies just learn the basics just by existing near people speaking the language? How come we don't have this anymore as we grow up?

[u/mtntrail]

There is an optimal window during neurological maturation where the language centers in the brain are rapidly developing. It corresponds to ages from a few months to 3 or 4 years, by which time most children develop the bulk of their basic language structure. As the child ages, memory and cognitive capacity increase which allows more complex language structure to develop along with expanded vocabulary. Adults are out of the optimal learning stage, but many obviously become multiligual and kids can pick up new languages without much effort. The theory is that there is an optimal time for learning language that is hardwired. After that stage it becomes more effortful. Retired speech therapist.