"know what is what" in Chinese (Traditional)
分得清楚明白事理
Definition
能夠分辨什麼纔是真正重要的，或者能夠看清人或事物的本質，不容易被愚弄。
Usage Notes (Chinese (Traditional))
多用於非正式場合，形容有經驗或有判斷力的人。常見於'他很明白事理'這類說法，強調實際經驗與常識。
Examples
After years in business, she knows what is what.
做了多年生意，她已經**分得清楚**了。
You must know what is what before making a decision.
做決定前，你必須**明白事理**。
He doesn't know what is what yet—he's new here.
他還不**分得清楚**——他剛來這裡。
Don't worry, I know what is what around here.
別擔心，這裡我**明白事理**。
She pretends to be an expert, but she doesn't really know what is what.
她裝作是專家，其實根本不**明白事理**。
After getting burned once, he learned to know what is what.
喫過一次虧後，他學會了**分得清楚**。