expression, godan verb (-ru)
become experienced; show seasoned skill
Used for people or their skills that have matured through many years of practice. Often implies a positive, reliable quality.
彼の包丁さばきは年季が入っている。
His knife skills show years of experience.
あの職人の仕事ぶりには年季が
That craftsman's work really shows seasoned skill, doesn't it?
expression, godan verb (-ru)
become worn; show its age
Used for objects that have aged or become worn through long use. Can be neutral or slightly negative, implying shabbiness.
この革のソファは年季が入っていて、味わいがある。
This leather sofa has aged and has a lot of character.
彼のスーツは年季が入って、あちこち擦り切れている。
His suit is worn and frayed in places.