mother tongue; native language
Su lengua materna es el francés.
His native language is French.
Ella habla inglés como si fuera su lengua materna.
She speaks English as if it were her native language.
Uno debería amar su lengua materna.
One should love one's mother tongue.
Russian is his native language.
El español es su lengua materna.
Spanish is his native language.
His native language is Russian.
El francés es su lengua materna.
French is his native language.
Había olvidado que su lengua materna era el francés.
She had forgotten that her native language was French.
El ruso no es su lengua materna.
Russian is not his native language.