Explanation

  • An idiomatic, often humorous or sarcastic way to say that something will never happen because it's completely impossible (like pigs being able to fly).

Origin

  • This idiom uses the absurd and impossible image of pigs flying to denote utter impossibility.
  • Variations existed earlier (e.g., when pigs whistle), dating back to at least the 17th century.
  • The fly version gained traction, possibly influenced by the general atmosphere of fantastical impossibilities in works like Lewis Carroll's, though the exact phrase isn't in Alice. It became well-established in the 19th/20th centuries.

Alternatives

Slang/Informal:

  • Yeah, right (Sarcastic)
  • Get outta here (Expressing disbelief)
  • As if!
  • Snowball's chance in hell
  • Fat chance

Vulgar/Emphatic:

  • When fucking pigs fly
  • Like fucking hell / Fuck that

Milder/Formal:

  • That's highly improbable
  • I seriously doubt that will ever happen
  • That seems entirely impossible

Situational Appropriateness

  • Informal.
  • Humorous but can easily come across as sarcastic or dismissive.
  • Avoid in formal settings or when discussing serious possibilities.

Misunderstanding Warnings

  • Non-native speakers need to understand it's a fixed idiom for impossibility, based on an absurd image, and not related to actual pigs or aviation.

Examples

  • He promises he'll start saving money? Yeah, when pigs fly.
  • She'll clean her room without being asked when pigs fly.

Dialogue

Liam: Do you think the boss will finally approve our request for new computers this year?

Nora: Ha! When pigs fly. Remember last year's budget meeting? Not a chance.

Liam: Yeah, wishful thinking, I guess.

Social Media Examples

  • Post: My cat will learn to fetch the newspaper when pigs fly. #CatLogic #ImpossibleDreams
  • Comment Thread: User A: Maybe THIS year my team will finally win the championship! User B: Sure... when pigs fly. 😉

Response Patterns

  • Laughter or amusement: Haha, true!
  • Agreement on the impossibility: Yeah, exactly. / So, never then?
  • Mild offense if used dismissively about something the listener hoped for: That's a bit harsh!

Common Follow-up Questions/Actions

  • Usually ends the discussion of that possibility or prompts agreement/laughter.
  • Someone might jokingly respond, Well, I saw one flapping its wings yesterday!

Conversation Starter

  • No. A response indicating impossibility, often sarcastically.

Intonation

  • Often said with a sarcastic, dismissive, or humorous tone.
  • Stress usually on pigs and fly. When PIGS FLY.
  • Sometimes accompanied by a slight laugh, smirk, or eye-roll.

Generation Differences

  • Well-understood across generations.
  • Might be seen as slightly quaint, folksy, or cliché by some younger people, but still widely recognized.

Regional Variations

  • Widely known in most English-speaking countries.
  • Pigs might fly is a common variant, perhaps slightly more prevalent in British English, often used with a tone of skepticism rather than outright impossibility.
Not in a million years