know somebody/something inside out

US /noʊ ˈsʌm.bə.di ˈsʌm.θɪŋ ˌɪn.saɪd ˈaʊt/
UK /noʊ ˈsʌm.bə.di ˈsʌm.θɪŋ ˌɪn.saɪd ˈaʊt/
"know somebody/something inside out" picture
1.

conocer al dedillo, conocer a fondo

to know someone or something extremely well

:
She's worked here for twenty years, so she knows the company inside out.
Ha trabajado aquí durante veinte años, así que conoce la empresa al dedillo.
He's a local, so he knows this area inside out.
Es de aquí, así que conoce esta zona al dedillo.