you can never tell
US /juː kən ˈnev.ər tel/
UK /juː kən ˈnev.ər tel/

1.
nunca se sabe, você nunca pode dizer
used to say that it is impossible to know what will happen or what is true
:
•
It might rain later, you can never tell.
Pode chover mais tarde, nunca se sabe.
•
She said she'd be here, but you can never tell with her.
Ela disse que estaria aqui, mas nunca se sabe com ela.