Language is full of colorful ways to describe situations, and idioms are among the most creative. An idiom is a phrase whose meaning is different from the literal words used.
For example, when we say, “It’s raining cats and dogs,” we don’t mean animals are falling from the sky—it simply means it’s raining heavily.
When it comes to expressing that something is never going to happen, English offers a treasure chest of quirky idioms. These expressions add humor, style, and clarity to conversations. Instead of simply saying,
“That’s impossible,” you can use phrases like “when pigs fly” or “not in a million years.” Idioms for impossibility are powerful because they make communication more engaging, memorable, and even fun.
In this guide, we’ll explore over 50 idioms that mean something is not going to happen, grouped into different themes for easy understanding.
Did You Know?
The famous idiom “when pigs fly” dates back to the 1600s and was originally used sarcastically in Scotland. Writers and poets loved it because of its humor—imagining pigs with wings was the ultimate way to say something was absurd or impossible.
Idioms Based on Animals
When Pigs Fly
Meaning: Something that will never happen.
Example: “He’ll clean his room without being asked—when pigs fly!”
Alternative: “Not in this lifetime.”
Note: Popular in daily conversation, usually informal and humorous.
When Hell Freezes Over
Meaning: Something absolutely impossible.
Example: “She’ll apologize—when hell freezes over.”
Alternative: “Over my dead body.”
Note: Often used in sarcastic or strong informal speech.
A Snowball’s Chance in Hell
Meaning: No chance at all.
Example: “That team has a snowball’s chance in hell of winning the championship.”
Alternative: “Fat chance.”
Note: Informal, sometimes dramatic.
Like Teaching a Fish to Climb a Tree
Meaning: Asking someone to do the impossible.
Example: “Expecting him to sit quietly is like teaching a fish to climb a tree.”
Alternative: “Mission impossible.”
Note: Casual and witty.
As Likely as Finding a Unicorn
Meaning: Impossible or extremely rare.
Example: “Getting tickets now is as likely as finding a unicorn.”
Alternative: “One in a billion.”
Note: Lighthearted, informal.
As Likely as a Chicken Growing Teeth
Meaning: Will never happen.
Example: “You’ll see him being polite as likely as a chicken growing teeth.”
Alternative: “As rare as hen’s teeth.”
Note: Humorous, old-fashioned.
Idioms Based on Time and Chances
Not in a Million Years
Meaning: Absolutely never.
Example: “Not in a million years would I betray my friend.”
Alternative: “Never ever.”
Note: Widely used in both casual and serious contexts.
Once in a Blue Moon (with irony)
Meaning: Something so rare it’s almost never.
Example: “He cleans the house once in a blue moon.”
Alternative: “Hardly ever.”
Note: Can be used jokingly or literally.
Till Kingdom Come
Meaning: Forever, or never until the end of time.
Example: “You’ll be waiting till kingdom come for that apology.”
Alternative: “Till doomsday.”
Note: More poetic, used in literature and songs.
Not in This Lifetime
Meaning: Impossible within one’s life.
Example: “He’ll quit chocolate? Not in this lifetime.”
Alternative: “When pigs fly.”
Note: Common in speech, casual.
A Fat Chance
Meaning: No chance at all.
Example: “You think she’ll forgive you? Fat chance.”
Alternative: “Slim to none.”
Note: Sarcastic tone, informal.
Slim to None
Meaning: Almost zero possibility.
Example: “The chance of winning is slim to none.”
Alternative: “No way.”
Note: Neutral, daily conversations.
Chance in a Million (used negatively)
Meaning: Extremely unlikely.
Example: “He’s got a chance in a million of passing that exam.”
Alternative: “Snowball’s chance in hell.”
Note: Formal and informal.
Idioms Based on Places and Nature
Until the Cows Come Home
Meaning: Waiting endlessly, but in vain.
Example: “You can argue until the cows come home, but I won’t change my mind.”
Alternative: “Forever and ever.”
Note: Rural origins, humorous tone.
Until the Twelfth of Never
Meaning: Something that won’t happen until an impossible date.
Example: “I’ll forgive him the twelfth of never.”
Alternative: “Never in a million years.”
Note: Poetic, sometimes romanticized.
When the Stars Fall
Meaning: Impossible event.
Example: “He’ll admit he was wrong when the stars fall.”
Alternative: “When pigs fly.”
Note: Slightly literary.
Until the Mountains Move
Meaning: Something impossible or extremely unlikely.
Example: “You’ll see me quit coffee until the mountains move.”
Alternative: “When hell freezes over.”
Note: Literary or expressive.
Until Doomsday
Meaning: Never or until the end of the world.
Example: “She’ll keep complaining until doomsday.”
Alternative: “Till kingdom come.”
Note: Dramatic and formal.
Not in God’s Green Earth
Meaning: Absolutely not.
Example: “Not in God’s green earth will I trust him again.”
Alternative: “Over my dead body.”
Note: Strong, formal or informal.
Everyday Expressions for Impossibility
No Way
Meaning: Impossible, not going to happen.
Example: “No way I’m lending him money again.”
Alternative: “Not happening.”
Note: Very common and casual.
Over My Dead Body
Meaning: I will never allow it.
Example: “You’ll marry her? Over my dead body.”
Alternative: “When hell freezes over.”
Note: Strong, emotional tone.
Out of the Question
Meaning: Not allowed or impossible.
Example: “Taking a loan now is out of the question.
Alternative: “Not possible.”
Note: Often used in professional settings.
Not Happening
Meaning: Refusal or denial.
Example: “You want me to work on Sunday? Not happening.”
Alternative: “No way.”
Note: Informal, direct.
Not a Hope in Hell
Meaning: No possibility at all.
Example: “He hasn’t a hope in hell of winning.”
Alternative: “Snowball’s chance in hell.”
Note: British English, informal.
Not by a Long Shot
Meaning: Not at all, no chance.
Example: “She isn’t the best singer, not by a long shot.”
Alternative: “No way.”
Note: Informal and often used in debates.
Dream On
Meaning: That will never happen.
Example: “You think you’ll beat me? Dream on!”
Alternative: “Keep dreaming.”
Note: Casual, often playful.
Forget It
Meaning: It’s impossible or not going to happen.
Example: “You want my car? Forget it.”
Alternative: “No chance.”
Note: Very common in daily speech.
Not in the Cards
Meaning: Not destined to happen.
Example: “A promotion this year isn’t in the cards for me.”
Alternative: “Not meant to be.”
Note: Common in American English.
Beyond the Realm of Possibility
Meaning: Totally impossible.
Example: “That idea is beyond the realm of possibility.”
Alternative: “Out of the question.”
Note: Formal usage.
How to Use These Idioms in Daily Life
Idioms about impossibility can be used in speaking, writing, and even in professional settings if chosen carefully.
- In conversations: Use light idioms like “when pigs fly” or “dream on” with friends to sound humorous.
- In writing: Use stronger idioms like “out of the question” or “beyond the realm of possibility” in essays, reports, or articles.
- At work: Polite idioms such as “not in the cards” or “out of the question” work best in emails or meetings. Avoid overly casual expressions like “forget it” in formal contexts.
Common Mistakes Learners Make With Idioms
- Using idioms literally:
❌ “When pigs fly, I will see pigs flying.”
✔️ Correct: “I’ll believe he’s honest when pigs fly.” - Mixing idioms incorrectly:
❌ “He has a snowball’s chance when pigs fly.”
✔️ Correct: Use only one idiom at a time: “He has a snowball’s chance in hell.” - Using informal idioms in formal settings:
❌ In a business email: “Your idea will work when pigs fly.”
✔️ Correct: “Your idea is out of the question.”
Frequently Asked Questions
Q1: What does “when pigs fly” mean?
It means something is impossible or will never happen. It’s one of the most common idioms for impossibility.
Q2: Are idioms like “snowball’s chance in hell” polite?
Not really. This idiom is strong and dramatic, so it’s best for informal speech, not polite or professional contexts.
Q3: Can idioms for impossibility be used in writing?
Yes, but choose carefully. “Out of the question” is suitable for formal writing, while “dream on” is best for casual texts or stories.
Q4: Are these idioms used worldwide?
Many are common in English-speaking countries like the US, UK, Canada, and Australia. Some may be more popular regionally.
Q5: Why should I learn idioms instead of just saying “never”?
Idioms add flavor, style, and personality to your English. They help you sound more natural and engaging.
Conclusion
Idioms are a wonderful way to express ideas creatively, and when it comes to showing impossibility, English has dozens of clever phrases. From the playful “when pigs fly” to the serious “out of the question,” these idioms allow you to express doubt, refusal, or impossibility in vivid ways.
Whether you’re chatting with friends, writing essays, or working professionally, choosing the right idiom can make your communication more lively and powerful
So the next time you want to say something is never going to happen, try one of these colorful idioms—you’ll sound more fluent and natural instantly.
