To master a language is not an easy thing.

掌握一门语言不是一件容易的事情。

youdao

To master a language, words, and grammar rules are not enough. You must do a lot of reading.

要掌握一门语言，光有单词和语法规则是不够的，你得大量阅读。

youdao

Students are expected to master a second language.

学生们应该掌握一门第二语言。

《柯林斯英汉双解大词典》

He was a master of English style and prose, and his work ranks among the very greatest in this or any other language.

他是英文写作的大师，他的作品不管在哪种语言里,都是佼佼者。

耶鲁公开课 - 政治哲学导论课程节选

You can appreciate how impressive this is only if you have attempted to master a foreign language yourself.

FORBES: A New International Business Language: Globish

Why does a competent citizen have to master a state language?

UNESCO: The International Mother Language Day-2012

But he's also careful to point out that Macaulay was racist, harboured prejudices about native Indians and customs and, despite being a linguist, did not attempt to master any Indian language.

BBC: Recalling Thomas Macaulay's English legacy