master

noun1 of 2

1. someone who has control over others; 2. someone who is very skilled at doing something

• “It takes a long time to master a foreign language.”Tatoeba
• “Mastering a language with a different word order is challenging.”Tatoeba

Sentences from Tatoeba show real usage. A word can have several meanings, so a sentence may use another one.

verb2 of 2

To learn to a high degree of proficiency.