Tell (someone) what's what phrase
To apprise someone of the truths of most essential information (about someone or something).
He made an important decision without telling his wife what's what.
Tell me what's what immediately if there are any changes in her condition.
You should have told the patient what's what instead of hiding the unpleasant truth from him.
To inform as many people as possible of something.
To surprise someone with an unexpected and difficult-to-handle problem, scenario, or inquiry.
To apprise someone of something new.
To educate, inform someone about something or provide information to someone.
To inform someone about something or get them involved in something.
The verb "tell" must be conjugated according to its tense.
The origin of this phrase is not clear.
If someone or something stands/sticks out like a sore thumb, they are so noticeable that the surrounding people and things notice them.
The dress codes of the wedding are blue and green, but Liza wore the red dress - she stuck out like a sore thumb.