mother tongue

 Longman Dictionary of Contemporary English 5++朗文当代英语 5++LDOCE 5++朗文 5++

Related topics: Languages

ˌmother ˈtongue noun [countable] especially British English  SLLyour mother tongue is the first and main language that you learnt when you were a child 母语 SYN native language/tongue children for whom English is not their mother tongue 母语不是英语的儿童

Examples from the Corpus

mother tongue• More than one-fifth of the population had German as their mother tongue.

ˌmother ˈtongue nounChineseSyllable  

Corpus main first the mother your and language is tongue

mother tongue
ˌmother ˈtongue noun [countable] especially British English
your mother tongue is the first and main language that you learnt when you were a child
   SYN  native language/tongue:
    children for whom English is not their mother tongue

mother tongueBrE /ˌmʌðə ˈtʌŋ/ 🔊NAmE /ˌmʌðər ˈtʌŋ/ 🔊 nounthe language that you first learn to speak when you are a child 母语；本国语 SYN first language