Explanation

  • An exclamation expressing strong surprise, confusion, bewilderment, or sometimes annoyance.
  • On earth acts as an intensifier, emphasizing the speaker's shock or inability to comprehend something.

Origin

  • Using on earth as an intensifier in questions (What/Why/How/Who on earth...?) has a long history in English, dating back potentially to the 16th or 17th century.
  • It adds a strong emphasis, implying that something is so strange or unexpected that it challenges the norms of this world ('earth'). It's a way of asking What in the entire world is this?

Alternatives

Slang/Informal:

  • What the heck? / What the hay? (Milder euphemisms)
  • What gives?
  • What's the deal?
  • Say what? (Expresses confusion/disbelief)

Vulgar/Emphatic:

  • What the hell?
  • What the fuck? / WTF? (Very common, very vulgar)

Milder:

  • What in the world?
  • Goodness me, what's that?
  • My goodness!
  • Heavens! What is this? (Dated)

Situational Appropriateness

  • Informal to semi-formal.
  • Generally acceptable in most situations unless extreme formality is required.
  • It's less harsh than alternatives using hell or fuck, making it a relatively safe choice for expressing strong surprise.

Misunderstanding Warnings

  • Generally well-understood as an expression of strong surprise or confusion.
  • The main risk is misjudging the level of formality; it's not suitable for very formal contexts.

Examples

  • What on earth is that terrible smell?
  • (Seeing a bizarre outfit) What on earth is she wearing?
  • He quit his job with no notice? What on earth was he thinking?
  • What on earth happened here? The room is a mess!

Dialogue

Anna: (Opens the fridge) What on earth...? There's a shoe in here!

Ben: A shoe? Seriously? Let me see! What on earth is it doing there?

Anna: I have absolutely no idea.

Social Media Examples

  • Tweet: Just saw a squirrel riding a skateboard. What on earth? 😂 #Wildlife #CityLife
  • Post: My phone just updated and now I can't find anything. What on earth did they do?! #TechFail #Confused
  • Comment: What on earth is that recipe? Pickles and peanut butter??

Response Patterns

  • Explanation: It's the garbage truck., That's the new fashion trend., I have no idea., It was the dog.
  • Shared Confusion/Surprise: I know, isn't it weird?, Beats me., Your guess is as good as mine.
  • Annoyance (if the tone was annoyed): Sorry, I'll clean it up.

Common Follow-up Questions/Actions

  • Investigating the source of the surprise/confusion: Walking towards the smell, looking closer at the object.
  • Asking clarifying questions: What is that thing?, Why did they do that?, Who made this mess?
  • Expressing further opinion: That's disgusting!, That's ridiculous!

Conversation Starter

  • No.
  • Reaction to observing something strange or unexpected.

Intonation

  • Exclamatory, often with a high or falling pitch expressing shock or confusion.
  • Stress typically falls strongly on WHAT and EARTH. WHAT on EARTH?
  • Can have a rising intonation if genuinely seeking an answer while still expressing surprise: What on EARTH is that?

Generation Differences

  • Used across generations. Might be perceived as slightly more formal or less intense than What the heck/hell/fuck by younger speakers, but still very common.

Regional Variations

  • Widely used and understood in all major English-speaking regions.
You don't say