mother tongue

英 [ˌmʌðə ˈtʌŋ]

美 [ˌmʌðər ˈtʌŋ]

n. 母语; 本国语

牛津词典

noun

母语;本国语;本族语
Yourmother tongueis the language that you learn from your parents when you are a baby.

noun

Today students of English, even if English is their mother tongue cannot understand his jokes.
今天学习英语的学生，甚至是以英语为母语的人们，仍然听不懂的玩笑。
You're flunking english. that's your mother tongue, and stuff.
你的英文挂了。那是你的母语，这还聪明。
His mother tongue was Korean but spoke fluent English.
他的母语是朝鲜语，但英语流利。
First, because Mandarin Chinese is not my mother tongue, I took a two-month crash course.
首先，因为普通话不是我的母语，我先上了两个月的语言课。
Instead we learned or acquired our mother tongue by communicating with the people around us.
我们的母语是通过和我们周围人们的交流而学习或获得的。
The scholar is well versed in Latin, not to speak of English which is his mother tongue.
那位学者精通拉丁语，至于他的本族语英语就更不用说了。
I was brought in Bolin and french is my mother tongue.
你猜对了！我生长在法语是我的母语。
His mother tongue is Portuguese.
他的母语是葡萄牙语。
He wrote the article in his mother tongue.
他用母语写的文章。
Mother tongue and the first foreign language both transfer the vowel pronunciation of the second foreign language.
母语和第一外语对第二外语的元音发音都存在着迁移作用。