Dear friends, how do you describe in your language someone who has learned a language since birth? In English, people say "native speaker", in German "Muttersprachler" (mother tongue speaker). Which term would you use in your language & where does it come from? Thanks in advance.

Thanks a lot for the responses. It seems that "mother language" is the most common expression. But Greek & Croat have also expressions for a "natural, authentic" speaker. Are there any other languages which can make such a distinction (between mother language & natural language)?