know what's what

US /noʊ wʌts wʌt/
UK /noʊ wʌts wʌt/
"know what's what" picture
1.

知道是怎麼回事, 了解情況

to have a good understanding of a situation or of how things work

:
She's been in this business for years, so she really knows what's what.
她在這個行業多年,所以她真的知道是怎麼回事
You need to spend some time learning the ropes if you want to know what's what around here.
如果你想在這裡知道是怎麼回事,你需要花一些時間學習竅門。