mother tongue

US /ˈmʌð.ər ˌtʌŋ/
UK /ˈmʌð.ər ˌtʌŋ/
"mother tongue" picture
1.

母語

the language that a person has grown up speaking from childhood; the native language of a person or a group of people

:
English is my mother tongue, but I also speak French fluently.
英語是我的母語,但我也會說流利的法語。
Learning a new language is easier if you have a strong foundation in your mother tongue.
如果你的母語基礎紮實,學習一門新語言會更容易。