First language and Native language

First language noun - One's native language; the language learned by children and passed from one generation to the next.

Native language and first language are semantically related. In some cases you can use "Native language" instead a noun phrase "First language".

Native language noun - The language that a person has spoken from earliest childhood.

First language and native language are semantically related. You can use "First language" instead a noun phrase "Native language".