Phrase vs. Idiom vs. Expression – What’s the Difference?

Is a “phrase” the same thing as an “idiom”? What about an “expression”? Is that the same thing as an “idiom”? Do all of these terms mean the same thing? Or do they all refer to different things? This article will explain all of these questions.

Phrase vs. Idiom vs. Expression – What’s the Difference?

A “phrase” is a group of words that make sense when spoken together, but are not usually a complete sentence. An “idiom” is a similar thing, but an “idiom” has a meaning not derived from the literal words themselves. An “expression” is a phrase that is very common.

Phrase vs. Idiom vs. Expression

The way to conceptualize it is like this: All idioms are phrases, and all expressions are also phrases. But a phrase is not necessarily an idiom, or an expression.

They can overlap, in the sense that a phrase can also be an idiom or an expression, and so they could be interchangeable, synonyms in that specific context.


A “phrase” is a group of words that, when combined, express an idea that is logical and makes sense. A phrase is usually a part of a sentence, but in certain contexts can be an entire sentence. In casual contexts we might speak just in phrases instead of full sentences.

According to the Cambridge English Dictionary, a “phrase” is “a group of words that is part of, rather than the whole of, a sentence”.

So according to this definition, what distinguishes a phrase is the fact that it is not a full sentence, but is instead just a segment of it.

Here are some example sentences that include the proper use of “phrase” in them:

  1. I remember that when we were talking, she said a specific phrase that really stuck out in my mind.
  2. The phrase was written with awkward, rushed handwriting; it was clear that he’d had to leave early.
  3. When you look at this phrase you will notice that, upon further inspection, it doesn’t make sense.
  4. This specific phrase I’m convinced has a secret message hidden inside of it.
  5. She wrote a phrase on the whiteboard, took one final look at the class, and left, forever.


An “idiom” is a specific grouping of words that, when put together, have a meaning that you couldn’t discern just by the literal definitions of the individual words themselves. Idioms often have meanings that are metaphorical in a way that has to be discerned by the context where they’re used.

According to The Cambridge English Dictionary, an “idiom” is “a group of words in a fixed order that has a particular meaning that is different from the meanings of each word on its own”.

Therefore we can see how you have to use context clues or a definition to figure out what many idioms mean.

Here are some example sentences that will teach you how to use the word “idiom” in your daily life:

  1. That specific idiom is one I don’t use often, but it’s very useful for sure.
  2. I remember that day he coined a new idiom, and we all laughed about it in the end.
  3. She got a tattoo of an idiom that is very important and dear to her heart.
  4. His emblematic idiom was written across the jacket in bold golden lettering.
  5. That’s a wild idiom to bring up here but I sort of get what you mean by it.


An “expression” is a specific grouping of words that is used often enough together to push it beyond the territory of mere “phrase”. When a phrase becomes common, it becomes an expression, which is a thing that people often say.

According to The Cambridge English Dictionary, an “expression” is “a word or group of words used in a particular situation or by particular people”.

An expression can also be an idiom, because they are similar concepts that can have overlap (one is based on common use, the other on its meaning).

These example sentences will showcase the correct way in which you can use “expression”:

  1. That’s an odd expression to use in that context, so I’m trying to figure out what she meant by it.
  2. He wrote down an expression that he had heard many years ago, in a distant country.
  3. The subtitle for the essay is an expression that my mother told me decades ago.
  4. She’s trying to make sure everyone knows that using that expression is morally wrong.
  5. Their list of common expressions was really interesting, and made me think about language.

Which Is Used the Most?

According to data gathered by the Google Ngram Viewer, “expression” is, by far, the most popular of these phrases in the modern day. It’s followed by “phrase” and, finally, “idiom” is at the bottom of the popularity ranking.

Phrase vs. Idiom vs. Expression usage

Since the year 1900, all three of these expressions have stayed in the positions which they currently inhabit. There hasn’t been a point where that position could’ve changed.

However, an interesting fact about the information compiled is that “idiom” and “phrase” have stayed very consistent in how much use they get.

Meanwhile, the use of “expression” has varied wildly, and has actually grown over the decades.

Final Thoughts

A “phrase” is a grouping of words that means a specific thing. When that phrase has a meaning that can’t be discerned by just the individual word meanings, it’s an “idiom”. And when that phrase becomes common in its use, it’s an “expression”.