Definition of know what's what in English:

know what's what

phrase

informal
  • Be experienced and competent in a particular area.

    • ‘Peritz, in truth, is an inherently humble guy who knows what's what.’
    • ‘Yes, you guessed it - the subject is the upcoming election, and the political scientists think they know what's what.’
    • ‘Hire a crew of people who have put on such shows before, and who know what's what.’
    • ‘He's a good boy and old enough to know what's what out there.’
    • ‘You may not make much money, but after six months of dedicated effort you should have a winning portfolio that will convince your prospective employer that you know what's what and can do the job.’
    • ‘Ads nowadays, especially on TV, portray blokes as stupid and disorganised, while women always know what's what.’
    • ‘The Berlin film audience, however, immediately erupted into spontaneous applause, proving that we 21 st-century folk know what's what.’
    • ‘You think you've seen life, think you know what's what, but you haven't, and you don't.’
    • ‘I think everyone can be their own researcher now really; you can be in charge of your own affairs and know what's what.’
    • ‘You don't need a university education to understand this world and to know what's what.’