a trece prin ciur şi prin dârmon / sită

to go through the test of adversity

to go / to pass through the mill

a fi trecut \a trece prin ciur şi prin dârmon / sită to have been / gone / passed through the mill

to know a thing or two

to be up to a thing or two

to know what's what

to be an old file

to be an artful dodger

to know the ropes

sl. to be up to snuff.