what's what
- idiom
- Informal
- Let's clarify the situation so that everyone knows what's what.
- know what's what
- tell what's what
- see what's what
Examples
-
Miz Smith told them what was what.
Fiction book (1994) -
We'll go there, and we'll see what's what.
-
So when he got home, I told him what was what.
-
I knew what was what, right from the start.
-
Now, I will tell you what's what.
-
And when we find out what's what, we have to keep it secret.
Fiction book (2001) -
"I suppose I must travel to Scotland and see what's what."
Fiction book (2001) -
"Then we'll take a look and see what's what."
Fiction book (1995) -
You know how you can tell what's what.
Fiction book (1994) -
I just thought I'd stop by to see what's what.
Synonyms
A complete, detailed report of events and facts
Small pieces of information about exact facts or a situation
How Clear
Surface Forms
Morphology
what's + what
The sense 'the important facts or true state of affairs' is not directly derivable from the words 'what' or the contraction 'what's' — the repetition forms an idiomatic fixed phrase ('what is what') whose pragmatic meaning cannot be compositionally inferred. A B1 learner who knows the constituents is unlikely to predict this usage without prior exposure, so it patterns as a language-specific idiom rather than a transparent composition.
Etymology
What's what comes from people asking the simple question 'what is what' while pointing at things to learn which thing is which. So the picture of naming the important items made the phrase mean 'the important facts'.