Cách sử dụng
"Mastery" means being really good at something, like a skill or a subject. It means you have learned everything you need to know about it and can do it with ease. You would use the word "mastery" when talking about a person who is an expert in their field or has become really skilled at something they have practiced a lot. For example, you could say, "He has achieved mastery in playing the guitar," which means he has become really good at playing the guitar after practicing it for a long time.