Anyone who’s tried to learn English knows the moment when a phrase like kick the bucket stops meaning a foot and a pail. Idioms—expressions whose real meaning has nothing to do with the words themselves—are everywhere, adding color but also tripping up learners and even native speakers sometimes.

4 related posts

Definition: Figurative phrase with non‑literal meaning (Grammarly writing guide) ·
Cultural reach: Every language has them (StudioBinder film and language resource) ·
Learner challenge: Surface meaning ≠ true meaning (Indeed Career Advice)

Quick snapshot

1Confirmed facts
2What’s unclear
  • Exact number of idioms in any language is hard to determine
  • The origin of many idioms is debated or unknown
3Timeline signal
  • The word idiom comes from Greek idios (personal) – ancient root (StudioBinder language history)
  • Idiomatic expressions have been documented for centuries across cultures (StudioBinder language history)
4What’s next
Key facts about idioms drawn from linguistic references
Fact Detail
Definition (Grammarly) Phrases whose meaning differs from the literal meanings of the individual words (Grammarly writing guide)
Figurative umbrella Idioms are a form of figurative language (Speech Therapy Store SLP resource)
Cultural specificity Idioms vary by language and dialect (StudioBinder film and language resource)
Learner difficulty True meaning is different from the surface meaning (Indeed Career Advice)
Example: break the ice Start communication or reduce awkwardness (StudioBinder)
Example: under the weather Feeling ill (StudioBinder)
Example: spill the beans Reveal a secret (StudioBinder)
Example: kick the bucket Die (Speech Therapy Store)
Classroom treatment Idioms fall under the umbrella of figurative language in common guides (IDC education site)

The pattern is clear: idioms are everywhere, they’re culturally rooted, and they force us to look beyond dictionary definitions.

What is the simplest definition of an idiom?

What does idiom mean?

In plain terms, an idiom is a group of words whose combined meaning is different from the literal definition of each word. For example, if someone says it’s raining cats and dogs, no animals are actually falling from the sky. The expression simply means heavy rain (Speech Therapy Store SLP resource).

Merriam-Webster defines an idiom as “an expression whose meaning cannot be understood from the combined meanings of its elements” (StudioBinder citing dictionary definition). That straightforward idea explains why idioms puzzle language learners: the individual words give no clue to the real meaning.

How is idiom defined in traditional grammar?

Traditional grammar treats idioms as fixed, non‑compositional phrases. They are part of figurative language, a category that also includes metaphors, similes, and personification (Grammarly writing guide). Unlike a metaphor, which creates a comparison, an idiom is a set expression that speakers use without thinking about the imagery behind it.

Most classroom guides group idioms under figurative language alongside other figures of speech (IDC education site). The catch: idioms can be the hardest to decode because they are so specific to a culture and time.

Bottom line: An idiom is a phrase that means something other than what the words say. Non‑native speakers should memorize the meaning rather than try to translate word‑by‑word, and native speakers should notice how many they use every day.
The upshot

Because idioms are frozen expressions, you can’t change the wording without sounding unnatural. Try “spilled the beans” – now try “spilled the peas.” You have to learn each one as a chunk.

What is an example of an idiom?

Common English idioms

A handful of idioms pop up again and again in everyday conversation. Here are a few with their literal origin and the figurative meaning:

  • Break the ice – start a conversation in a tense situation (StudioBinder)
  • Hit the sack – go to bed (YouTube ESL teacher)
  • Piece of cake – something very easy (YouTube ESL teacher)
  • Under the weather – feeling sick (StudioBinder)
  • Spill the beans – reveal a secret (StudioBinder)
  • Kick the bucket – die (Speech Therapy Store)
  • Break a leg – good luck (Speech Therapy Store)
  • Raining cats and dogs – heavy rain (Speech Therapy Store)
  • By the skin of your teeth – barely, narrowly (StudioBinder)

What is a famous idiom?

One of the most widely recognized idioms in English is break a leg, used to wish performers good luck before a show. The exact origin is debated—some trace it to theater superstitions, others to an old German expression—but its meaning is universally understood among English speakers (Speech Therapy Store).

Pattern: Famous idioms often have backstories that we forget as the expression becomes standard. The meaning survives even when the original context fades.

How do you explain idioms to a child?

Simple idioms for kids

The best way to explain an idiom to a child is through a concrete, silly example. Take it’s raining cats and dogs. You can say: “When we say this, we don’t mean animals are falling from the sky. We mean it’s raining very hard.” (Speech Therapy Store pediatric resource).

  • Use pictures: draw a cartoon of cats and dogs raining, then a picture of a downpour.
  • Tell a short story that ties the idiom to a feeling (e.g., “You were so tired you could hit the sack right now”).
  • Practice with everyday situations: after a test, say “That was a piece of cake.”

How to teach idioms to children

Speech‑language pathologists recommend starting with idioms that kids encounter frequently and that have memorable imagery (Speech Therapy Store). Games like “match the idiom to its meaning” or “draw the literal and figurative version” help solidify the concept.

Bottom line: Kids learn idioms best when they connect the phrase to a concrete situation. Teachers should show the literal picture first, then reveal the figurative meaning—a little laughter makes it stick.
The paradox

Idioms are both the most colorful and the most frustrating part of language for children. A kid who says “it’s raining cats and dogs” feels clever; one who hears it for the first time is baffled. That’s exactly the cognitive leap parents and teachers need to bridge.

What are common idioms and their meanings?

9 idioms with definitions and example sentences

The following table maps nine widely used English idioms to their meanings and shows how native speakers deploy them in real sentences. For a deeper understanding of how these bodily processes work, you can explore a Digestive system diagram organs functions.

Common idioms sourced from language references
Idiom Meaning Example
Break the ice Start a conversation in a tense situation “He told a joke to break the ice at the meeting.” (StudioBinder)
Hit the sack Go to bed “I’m exhausted, time to hit the sack.”
Piece of cake Something very easy “The exam was a piece of cake.”
Under the weather Feeling ill “She stayed home because she was under the weather.” (StudioBinder)
Spill the beans Reveal a secret “Don’t spill the beans about the surprise party.” (StudioBinder)
Kick the bucket Die “My goldfish finally kicked the bucket.” (Speech Therapy Store)
Break a leg Good luck (especially in theater) “Break a leg tonight on stage!” (Speech Therapy Store)
Raining cats and dogs Heavy rain “We cancelled the picnic because it was raining cats and dogs.” (Speech Therapy Store)
By the skin of your teeth Barely, narrowly “He passed the test by the skin of his teeth.” (StudioBinder)

The implication: each of these idioms acts as a shortcut for a larger idea. Once you know the code, you can understand and use them instantly. The challenge is that you have to memorize the code—there’s no logical rule that predicts the meaning.

What is an idiom vs metaphor?

How is a metaphor different from an idiom?

Both idioms and metaphors are figures of speech that use words in a non‑literal way, but they work differently. A metaphor creates an explicit comparison between two things without using like or as—for example, “time is a thief.” An idiom is a fixed phrase whose meaning can’t be derived from the words themselves, such as “it cost an arm and a leg” meaning it was very expensive (Grammarly writing guide).

The biggest difference: you can invent a metaphor on the spot (“this job is a mountain”), but you cannot invent an idiom. Idioms are frozen expressions that a community has agreed upon over time.

Can an idiom be a metaphor?

Yes, many idioms are also metaphors. For example, “spill the beans” uses the image of spilling beans as a metaphor for revealing information. The phrase is both an idiom (because it’s a fixed expression) and a metaphor (because it compares disclosure to a physical accident). Language experts note that the categories overlap (StudioBinder language resource). The practical distinction for learners: if you can change the words without losing the meaning, it’s probably a metaphor. If you can’t, it’s an idiom.

Bottom line: Think of idioms as pre‑packaged metaphors that the language has locked into place. Teachers should use the metaphor concept to explain idioms but stress that idioms are fixed—no substitutions allowed.

What we know for sure — and what’s still murky

Confirmed facts

  • Idioms exist in every language studied so far (StudioBinder cultural linguistic survey)
  • Idioms are fixed expressions that cannot be changed without sounding unnatural (Grammarly writing guide)
  • Idioms are a subset of figurative language (IDC education site)
  • Idioms cause difficulty for language learners because the literal meaning doesn’t help (Indeed Career Advice)

What remains unclear

  • The exact number of idioms in English (or any language) is unknown — estimates range from a few thousand to over 25,000, but no definitive count exists.
  • The origin of many common idioms, such as “break a leg” or “raining cats and dogs,” is debated among linguists and historians.
  • Whether an idiom can be fully classified as a metaphor depends on the specific phrase and the grammatical framework used.

“Idioms are commonly used phrases or expressions whose meaning differs from the literal meanings of the individual words.”

— Grammarly writing guide (source)

“Idioms are often culturally specific and may vary by language and dialect.”

— StudioBinder film and language resource (source)

Editor’s note: These two definitions—one from a mainstream grammar guide, one from a media education site—agree on the core idea: idioms are cultural, fixed, and non‑literal. For writers and speakers, the implication is that learning idioms is like learning a second vocabulary, one that can’t be guessed from context alone.

Additional sources

tea4avcastro.tea.state.tx.us

For a deeper look at how figurative language works in everyday speech, you can explore common idiom examples that illustrate the concept further.

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Frequently asked questions

How many idioms are there in English?

Estimates vary widely, but linguistic databases list roughly 25,000 idiomatic expressions in English. However, no definitive count exists because new idioms appear and old ones fade.

Are idioms used in formal writing?

Generally, idioms are avoided in very formal or academic writing because they can sound informal or imprecise. In business communication and creative writing, idioms are common.

Why are idioms hard for non‑native speakers?

Because the phrase’s meaning cannot be deduced from the individual words. Learners must memorize each idiom as a separate vocabulary item (Indeed Career Advice).

What is the difference between an idiom and a proverb?

A proverb is a short, well‑known saying that gives advice (e.g., “Don’t count your chickens before they hatch”). An idiom is a phrase with a figurative meaning, not necessarily a lesson. Proverbs are often idiomatic, but not all idioms are proverbs.

Can idioms be translated literally?

Usually no. Translating an idiom word‑for‑word often produces nonsense or a completely different meaning. Skilled translators find an equivalent idiom in the target language or paraphrase the idea.

Do all languages have idioms?

Yes, every natural language appears to have fixed expressions that can’t be taken literally. The idioms themselves are culturally unique (StudioBinder).

How do idioms develop?

Idioms often start as metaphors or slang that catch on and become frozen. Over time the original imagery fades, and the expression becomes a standard idiom. For example, “bury the hatchet” comes from a Native American peace ceremony.

What is an idiom in a sentence example?

“She was feeling under the weather, so she stayed in bed.” Here under the weather is an idiom meaning ill.

For anyone learning English—or teaching it—the real‑world implication is clear: you can master the grammar and still miss the meaning if you don’t know the idioms. That’s why learners should absorb them through conversation, movies, and reading, not by memorizing lists alone. For native speakers, the gift is being able to say a lot with a few words.