熟练 (shú liàn): 연습하다.

He has worked at the company for five years and is very skilled at his job; new colleagues like to ask him for advice when they encounter problems.

In order to achieve good results in the competition, she practices the piano four hours every day; now her playing technique has become very proficient.

When she first started learning Chinese, she couldn't speak very fluently, but after two years of effort, her spoken Chinese is now very proficient.

This surgeon is highly skilled; he successfully completed the operation in just twenty minutes, and the patient and family were very grateful.

He has only been learning to use a computer for three months, but his typing speed is already quite proficient; he can type over eighty characters per minute.