proficient       
adjective uk/prəˈfɪʃ.ənt/ us/prəˈfɪʃ.ənt/
 熟练的;精通的
skilled and experienced
  a proficient swimmer 游泳好手 
 She's proficient in two languages. 她精通两门语言。 
 It takes a couple of years of regular driving before you become proficient at it. 得开上几年车,你才能熟练自如。