Some things in life just can’t happen. Like pigs flying, or your little brother doing the dishes without being told! In the USA, people love using funny and creative phrases to talk about things that seem totally impossible. These are called idioms. Idioms help make speech fun and give strong meaning using short, simple phrases.
In this article, we will look at idioms that talk about impossible things. These idioms are great for everyday talks, jokes with friends, or showing doubt when something seems too hard or unlikely. They are part of how many Americans speak. Whether it’s about an impossible task, a tricky person, or something that’s never going to happen, these sayings will help you sound like a real native speaker.
Idioms About Impossible
1. When pigs fly
Meaning: Something that will never happen
Example Sentence:
• He’ll clean his room without being asked—when pigs fly.
• My sister will share her candy when pigs fly.
Other ways to say: That’ll never happen, not in a million years
Fun Fact/Origin: Pigs can’t fly, so this joke shows how impossible something is.
Usage: Used to say something will definitely not happen.
2. A snowball’s chance in hell
Meaning: Almost no chance at all
Example Sentence:
• He has a snowball’s chance in hell of beating that video game without practice.
• She has a snowball’s chance in hell of waking up before 9 a.m.
Other ways to say: No chance, not likely
Fun Fact/Origin: A snowball would melt fast in a hot place like hell—showing no hope.
Usage: Used to talk about very slim chances.
3. Catch a unicorn
Meaning: Do something that’s not real or possible
Example Sentence:
• Finding that old toy in perfect condition is like trying to catch a unicorn.
• Getting Dad to dance is like catching a unicorn.
Other ways to say: Impossible to find, very rare
Fun Fact/Origin: Unicorns are mythical animals, which means they aren’t real.
Usage: Used to talk about rare or fake things.
4. Herd cats
Meaning: Try to control something very hard or wild
Example Sentence:
• Babysitting five toddlers is like herding cats.
• Getting my friends to agree is like herding cats.
Other ways to say: Out of control, hard to manage
Fun Fact/Origin: Cats don’t usually stay together or follow rules.
Usage: Used when something is wild or not organized.
5. Like squeezing water from a rock
Meaning: Trying to do something really hard or hopeless
Example Sentence:
• Getting him to do his homework is like squeezing water from a rock.
• Asking her to stop talking is like squeezing water from a rock.
Other ways to say: Very hard, almost impossible
Fun Fact/Origin: Rocks don’t have water inside, so squeezing one for water makes no sense.
Usage: Used for tasks that are nearly hopeless.
6. Not in a million years
Meaning: Something that will never happen
Example Sentence:
• Not in a million years will I eat a bug.
• He’ll admit he’s wrong—not in a million years.
Other ways to say: Never ever, that’ll never happen
Fun Fact/Origin: A million years is super long, making it sound funny and strong.
Usage: Used to show strong doubt.
7. Talk to a brick wall
Meaning: Speak to someone who won’t listen
Example Sentence:
• Asking him to clean is like talking to a brick wall.
• Mom said reminding me twice is like talking to a brick wall.
Other ways to say: No one listens, wasting words
Fun Fact/Origin: A wall can’t hear or talk, so it’s used to show someone won’t respond.
Usage: Used when someone is ignoring you.
8. Climb a greased pole
Meaning: Do something very hard or slippery
Example Sentence:
• Getting that job is like climbing a greased pole.
• Trying to win against her is like climbing a greased pole.
Other ways to say: Tough challenge, uphill battle
Fun Fact/Origin: A greased pole is too slippery to climb easily.
Usage: Used for very difficult tasks.
9. Nail jelly to a wall
Meaning: Do something that just doesn’t work
Example Sentence:
• Explaining math to him is like nailing jelly to a wall.
• Making her stop giggling is like nailing jelly to a wall.
Other ways to say: Can’t be done, useless
Fun Fact/Origin: Jelly is soft and wiggly—it can’t be nailed to a wall.
Usage: Used when trying something that doesn’t work.
10. Chase your tail
Meaning: Try hard but get nowhere
Example Sentence:
• I did chores all day but felt like I was chasing my tail.
• We’re chasing our tails with this messy project.
Other ways to say: Wasting time, going in circles
Fun Fact/Origin: Dogs chase their tails but don’t get anywhere.
Usage: Used for efforts that lead to nothing.
11. Like pulling teeth
Meaning: Something very hard to do
Example Sentence:
• Getting him to say sorry is like pulling teeth.
• It’s like pulling teeth to get my brother to take a bath.
Other ways to say: Hard to do, difficult
Fun Fact/Origin: Pulling teeth sounds painful and tough.
Usage: Used when someone refuses to do something.
12. Try to empty the ocean with a spoon
Meaning: A task that’s too big or silly
Example Sentence:
• Cleaning this room is like trying to empty the ocean with a spoon.
• Helping everyone at once is like emptying the ocean with a spoon.
Other ways to say: Way too big, impossible task
Fun Fact/Origin: A spoon is tiny—the ocean is huge.
Usage: Used for tasks that are too big to finish.
13. Fight city hall
Meaning: Try to go against strong rules or power
Example Sentence:
• Trying to change the school rules is like fighting city hall.
• Arguing with the coach is like fighting city hall.
Other ways to say: Can’t win, against the system
Fun Fact/Origin: “City hall” stands for the government or big authority.
Usage: Used when fighting a strong system.
14. Like teaching a fish to ride a bicycle
Meaning: Something that makes no sense at all
Example Sentence:
• Teaching him to bake is like teaching a fish to ride a bike.
• Giving a cat a bath is like teaching a fish to ride a bicycle.
Other ways to say: Doesn’t fit, nonsense
Fun Fact/Origin: Fish can’t use bikes—makes it sound silly.
Usage: Used when something is totally wrong or odd.
15. Can’t make a silk purse out of a sow’s ear
Meaning: Can’t turn something bad into something fancy
Example Sentence:
• That old toy is broken—you can’t make a silk purse out of a sow’s ear.
• His messy room won’t ever look like a palace.
Other ways to say: Can’t fix bad things, no way to polish it
Fun Fact/Origin: This comes from old times—meaning you can’t turn something ugly into something fine.
Usage: Used when you can’t improve something no matter what.
16. Like trying to lasso the wind
Meaning: Doing something you can’t catch or control
Example Sentence:
• Getting her to stay still is like trying to lasso the wind.
• My thoughts are like trying to lasso the wind before a test.
Other ways to say: Can’t catch it, too hard to hold
Fun Fact/Origin: Cowboys use lassos to catch animals—wind can’t be roped!
Usage: Used when something is wild and can’t be stopped.
17. Talk sense to a wall
Meaning: Try to explain to someone who doesn’t understand
Example Sentence:
• Talking sense to him is like talking to a wall.
• Trying to explain rules to my dog is like talking to a wall.
Other ways to say: No one listens, useless talk
Fun Fact/Origin: Walls can’t hear or change, so it means your words are wasted.
Usage: Used when someone won’t listen or change.
18. Run through a brick wall
Meaning: Try to do something impossible using only force
Example Sentence:
• He’s so stubborn, he’d try to run through a brick wall.
• She acts like she can run through walls to get what she wants.
Other ways to say: Can’t be done, hitting a wall
Fun Fact/Origin: No one can run through a wall—it’s solid and tough.
Usage: Used when someone tries too hard for something they can’t do.
19. Make a mountain out of a molehill
Meaning: Make a small thing seem too big
Example Sentence:
• She made a mountain out of a molehill over a missing pencil.
• He gets mad over tiny stuff—total mountain out of a molehill.
Other ways to say: Overreact, blow it out of proportion
Fun Fact/Origin: A molehill is small, a mountain is huge—so it’s exaggerating.
Usage: Used when someone makes a big deal out of nothing.
20. Like trying to hold water in your hands
Meaning: Try to keep control of something that slips away
Example Sentence:
• Managing my time during exams is like trying to hold water in my hands.
• Holding onto summer break feels like holding water in your hands.
Other ways to say: Can’t keep it, too hard to hold
Fun Fact/Origin: Water slips through fingers—it’s hard to keep.
Usage: Used for things that can’t be held or controlled.
21. Build castles in the air
Meaning: Make big dreams that aren’t real
Example Sentence:
• He’s building castles in the air if he thinks school will be canceled forever.
• I dreamed I could fly to school—that’s just a castle in the air.
Other ways to say: Wishful thinking, pipe dream
Fun Fact/Origin: You can’t build anything in the air—it’s not real ground.
Usage: Used when someone is dreaming about things that won’t happen.
22. Beat a dead horse
Meaning: Keep talking about something that’s over
Example Sentence:
• Let’s stop arguing—it’s like beating a dead horse.
• The teacher told him to stop asking. He was beating a dead horse.
Other ways to say: Move on, stop repeating
Fun Fact/Origin: Once a horse is gone, beating it does nothing.
Usage: Used when someone keeps going over something already done.
23. Get blood from a turnip
Meaning: Try to get something that isn’t there
Example Sentence:
• I have no money—you can’t get blood from a turnip.
• Asking him to be on time is like getting blood from a turnip.
Other ways to say: Nothing to give, impossible ask
Fun Fact/Origin: Turnips are plants—there’s no blood inside.
Usage: Used when someone expects something that’s just not possible.
24. Push a rope
Meaning: Try to do something that only works one way
Example Sentence:
• Telling my dog to clean up is like pushing a rope.
• Getting him to follow rules is like pushing a rope.
Other ways to say: Won’t work, not the right way
Fun Fact/Origin: You can pull a rope, but pushing it gets you nowhere.
Usage: Used when something just won’t work the way you want.
25. Like finding a needle in a haystack
Meaning: Something really hard to find
Example Sentence:
• Looking for my tiny toy in the sand is like finding a needle in a haystack.
• Finding the lost earring in the field was like finding a needle in a haystack.
Other ways to say: Super hard to find, almost lost
Fun Fact/Origin: Haystacks are big and messy—a tiny needle is nearly invisible in them.
Usage: Used when you can’t find something in a big mess.
26. Not worth a hill of beans
Meaning: Something is not important
Example Sentence:
• His promise means nothing—not worth a hill of beans.
• That toy’s broken—it’s not worth a hill of beans.
Other ways to say: Worthless, not valuable
Fun Fact/Origin: A small hill of beans isn’t much—so it means low value.
Usage: Used when something isn’t important.
27. Barking at the moon
Meaning: Complain or act in a way that changes nothing
Example Sentence:
• Yelling at traffic is like barking at the moon.
• Complaining about homework is just barking at the moon.
Other ways to say: Won’t help, useless complaining
Fun Fact/Origin: Dogs bark at the moon, but it stays the same.
Usage: Used when someone is yelling or upset without effect.
28. Waiting for cows to come home
Meaning: Wait forever for something that won’t happen
Example Sentence:
• You’ll be waiting for him to apologize until the cows come home.
• She’s waiting for her toy to fix itself—might be until cows come home.
Other ways to say: Forever, endless wait
Fun Fact/Origin: In farming, cows take a long time to return from the fields.
Usage: Used when someone is waiting for something that won’t happen soon.
Quiz: Idioms About Impossible
Instructions: Choose the correct meaning for each idiom. Each question has one correct answer. Use what you’ve learned from the idioms to find the best choice.
Question Key
1. What does “when pigs fly” mean?
A) Something that will happen soon
B) Something that will never happen
C) Something that always happens
2. If someone says “talking to him is like talking to a brick wall,” what does it mean?
A) He always listens
B) He’s ignoring you
C) He’s helping you
3. What does “not in a million years” mean?
A) It might happen tomorrow
B) It happened last year
C) It will never happen
4. If someone is “chasing their tail,” what are they doing?
A) Playing a fun game
B) Trying something with no result
C) Running fast to win a race
5. What does “like pulling teeth” mean?
A) Something easy to do
B) Something painful or very hard
C) Something silly
6. If you’re trying to “nail jelly to a wall,” what are you doing?
A) Making art
B) Doing something fun
C) Trying something that won’t work
7. What does “herding cats” mean?
A) Taking care of a farm
B) Doing something really hard to control
C) Playing with cats
8. What does “a snowball’s chance in hell” mean?
A) A very small chance
B) A good chance
C) No danger at all
9. If you’re “building castles in the air,” what are you doing?
A) Building sandcastles
B) Dreaming about things that aren’t real
C) Playing in the clouds
10. What does “like trying to hold water in your hands” mean?
A) You’re keeping water safe
B) You’re doing something easy
C) You’re trying to hold something that slips away
11. What does “beating a dead horse” mean?
A) Riding a horse
B) Trying to win a race
C) Talking about something that’s over
12. What does “waiting until the cows come home” mean?
A) Waiting a short time
B) Waiting forever
C) Waiting for dinner
Answer Key
- B. Something that will never happen
- B. He’s ignoring you
- C. It will never happen
- B. Trying something with no result
- B. Something painful or very hard
- C. Trying something that won’t work
- B. Doing something really hard to control
- A. A very small chance
- B. Dreaming about things that aren’t real
- C. You’re trying to hold something that slips away
- C. Talking about something that’s over
- B. Waiting forever
Wrapping Up
Idioms help us understand big ideas in a short and fun way. Americans use these sayings when talking about things that are too hard or won’t ever happen. From flying pigs to jelly on a wall, these phrases add humor and feeling to everyday talk.
Now that you’ve learned these 28 idioms about impossible things, you can spot them in books, movies, or even jokes. Try using a few the next time something seems way too hard. These phrases make talking more colorful—and more fun too.
