Helping Learners Understand Spoken English

Confusing English Phrase: What’s What

English can be VERY confusing! Idioms, phrasal verbs, slang, and other expressions used by native speakers can be difficult to understand. Today I want to talk about the following expression:

Let me tell you what’s what.

First, let’s break it down into two parts. Are you ready? Let’s dive in!

Part 1: Let Me Tell You

When combined with what’s what, let me tell you pretty much means exactly what it says:

  • I would like to tell you something.
  • Let me tell you something.
  • Allow me to tell you something.
  • Permit me to tell you something.

However, Let me tell you can also be used to emphasize something.

To emphasize something means to:

  • make it stronger
  • say it is important
  • highlight it

The words team, common, and success are highlighted in the image below in order to emphasize the importance of teams having a common purpose in order to succeed.

Punctuation Difference

When Let me tell you is used to emphasize something, the punctuation is different than when it is used with what’s what. Notice that there is no comma or period used in the sentence Let me tell you what’s what. because what’s what completes the sentence in the same way that something would. We could substitute it with other words as well.

For example, Let me tell you…

  • what happened yesterday.
  • what we need to do.
  • why I did that.
  • what the plan is.
  • what I’m thinking.

However, because let me tell you has this meaning of adding emphasis to what we are saying, we usually still feel that feeling of emphasis when it is used when we simply want to tell someone something or give them information about something. Let’s look at examples of both below.

Examples showing emphasis:

  • Let me tell you something. I could hardly believe my eyes!
  • Let me tell you, he was angry. I’ve never seen him that angry before.
  • Let me tell you, I will never go back to that restaurant again.
  • The keynote speaker was amazing, let me tell you.
  • It was the biggest spider I have ever seen, let me tell you.

Examples with what’s what:

  • Let me tell you what’s what. +
    • I heard that he is stepping down as CFO because of what happened.
    • If you want to be successful, you have to be willing to fail.
    • If we want to win this game, we have to come together as a team.
    • The best thing you can do at this point is to cross your fingers and hope for a miracle.
    • First we have to do a competitive analysis. After that, we can identify areas for improvement.

Part 2: What’s What

What’s what is the information or important facts you need to know in order to understand something. It’s the scoop (news, inside story). So, when someone says, “Let me tell you what’s what.” they mean, “Let me explain the information that you need to know.”


  • I have no idea what’s what. = I don’t understand.
  • I don’t know what’s what. = I don’t know what is going on.
  • I’ll tell you what’s what when I see you.
  • I wish I knew what was what.
  • I need to figure out what’s what.
  • When I know what’s what, I’ll let you know.
  • He has been working here for a long time. He knows what’s what.

Similar Expressions:

  • Let me tell you what’s happening.
  • Let me tell you what’s going on.
  • I have no idea what’s going on.
  • I’m (totally) clueless.
  • Let me clue you in.
  • What (the heck) is going on? (heck is used for emphasis and is a more polite version of hell)
  • I don’t know which side is up. (Used when someone is confused, disoriented or stressed out.)
  • I don’t know which end is up. (Used when someone feels confused, disoriented or stressed out.)

The Importance of Tone

One Expression, Two Possible Intentions/Feelings

Depending on the tone and the relationship between the people having the conversation, we can feel one of two ways when someone says Let me tell you what’s what.

  1. Talked down to
    • We feel talked down to if it is said with a harsher, know-it-all tone by someone who thinks they know better than us and wants to shed light on our lack of understanding or give us advice we did not ask for. We feel like they view us as inferior and not having enough knowledge.
  2. Helped
    • We feel thankful for someone’s help if they say it in a kind and gentle tone. They are simply explaining something that we want and need to know about. Perhaps we were late for a meeting or unable to attend a meeting, and we missed out on the important information. By telling us what’s what, they are doing us a favor by giving us useful information that we need.

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