native speaker
person who has spoken (a particular language) since birth, rather than learning it later 生来就说某种语言的人
a native speaker of French, Italian, etc 生来就说法语、 意大利语等的人
Her English accent is so good, you would think she was a native speaker. 她的英语口音很纯正, 谁都以为她生来就说英语.