Sharp as a tack
Meaning: very intelligent, very smart, very clever
Example: He may be old in years, but he's still as sharp as a tack and knows what he's talking about.
Выучи грамотный разговорный английский до уверенного владения всего за 9 месяцев по системе естественного усвоения иностранных языков. Жми!
Example: He may be old in years, but he's still as sharp as a tack and knows what he's talking about.