What are idiomatic phrases in English grammar?

This is the first of three lessons about Idiomatic Phrases (Idioms). To complete this course, read each lesson carefully and then unlock and complete our materials to check your understanding.   

– Learn the basics about English idiomatic phrases

– Study how their figurative nature defines idioms 

– Compare idioms with other types of figurative language, such as metaphors, similes and hyperbole. 

Lesson 1

Understanding the meaning of a word is as important, if not more important, than learning that word’s many forms or its grammatical variation. Grammar is theory and structure, and it changes between languages and from speaker to speaker. Meaning, however, is content – collectively agreed upon. Understand the meaning of a word or a phrase and a non-native can at least communicate in the most basic sense. But with thousands of words to learn, and with multiple interpretations of a word depending on the context, the study of word meanings is no small or easy task.

This challenge is particularly true of English idioms which attach irregular meanings to regular words, such as how ‘it’s raining cats and dogs’ can come to mean it’s raining heavily. The purpose of this short course on idiomatic phrases is therefore to introduce to students the basic concepts of the idiom (Lesson 1), exploring their usage in both general (Lesson 2) and academic contexts (Lesson 3). We provide well over a hundred examples for use in speech and writing, as well as worksheets that can be unlocked, downloaded and completed to improve knowledge and English proficiency.   

What is an idiom?

When it comes to selecting which words and phrases should be used in everyday English, one of the most creative (and fun) aspects of the language is the idiomatic phrase. Idioms are in fact so common in English that you may already recognise the two idioms being used in the example sentence below:

If you don’t recognise these two expressions however, then you may be somewhat lost as to what they mean. Yet with something like over 25,000 idiomatic phrases in the English language, this is an active area of word use that serious learners should pay attention to if they wish to sound at all native.


What makes idioms special?

For those who had never encountered the phrases ‘couch potato’ or ‘elephant in the room’ before, you might have guessed something like the following meanings:

But considering the original sentence, do these literal interpretations make any sense? Do you think there was actually an elephant in the room? And how could a person be a potato? Let’s take a look at their non-literal meanings instead:

From these non-literal (figurative; idiomatic) meanings we can now understand the original expression, that it is the laziness of the son that is the sensitive issue which requires attention. I.e., “Can you please do something about our lazy son?”. What these two examples therefore teach us is that idioms are figurative expressions which attach a non-literal meaning to a seemingly literal phrase, such as how ‘raining cats and dogs’ equates to ‘raining heavily’. In fact, it is this singular aspect that makes idioms so special, tricky and fun to learn. Idioms contradict the rules of compositionality in which the meaning of a whole is normally the sum of its parts.

Are idiomatic phrases always figurative?

While idioms are always figurative as this is part of what defines them, it’s important to remember that a phrase such as ‘elephant in the room’ can be interpreted in both literal and idiomatic ways. While it may seem unlikely, there will for example have been an elephant inside a room at some point in human history – perhaps in a zoo. It is therefore the listener’s responsibility to use context to determine idiomaticity, although this isn’t always easy. To see this literal and figurative alternation in action, it can be useful to exemplify phrasal verbs. After studying the two examples below, which do you think is more literal and which is more idiomatic?

Hopefully you were able to recognise that the orange examples using ‘put out’ and ‘turn down’ are the literal expressions. This is because the spatial meanings of the verbs ‘put’ and ‘turn’ can be determined from the meaning of the phrasal verb as a whole. In the second expressions in blue however, it’s not possible to determine the meaning ‘extinguish’ (stop the fire) or ‘decline’ (say no) from these verbs alone, and so the meanings of these phrasal verbs are figurative/idiomatic.


Are idioms the same as other figures of speech?

Metaphors, similes, hyperbole and proverbs are all types of figurative speech in English, but they should not be confused with idioms.

  • A metaphor is when something impossible is applied to an action or object through implicit comparison, such as in “man of steel” or famously “all the world’s a stage”.
  • Similar to metaphors, similes use explicit comparison to directly compare two things. They do this to make a description more vivid or emphatic, such as in “brave as a lion” or “faster than a speeding bullet”.
  • Hyperbole is an exaggeration of the truth beyond the realms of possibility, such as “I’ve told you a million times” or “missed by a mile”.
  • Proverbs are sayings which express (not always figuratively) a commonly accepted truth, such as “haste makes waste” or “a dog is a man’s best friend”.

Good work on completing this first lesson in our short course on idiomatic phrases in English. To learn about which idioms are most common in general English and academic English, continue studying with Lessons 2 and 3.

1 of 3 Lessons Completed


Once you’ve completed all three lessons in this short course about Idiomatic Phrases (Idioms), you might then wish to download our Lesson Worksheets to check your progress or print for your students. These professional PDF worksheets can be easily accessed for only a few Academic Marks.

Lesson 1 explores the topic: What are idiomatic phrases in English grammar? Our Lesson 1 Worksheet (containing guidance, activities and answer keys) can be accessed here at the click of a button. 

Lesson 2 explores the topic: Which idioms are most common in general English? Our Lesson 2 Worksheet (containing guidance, activities and answer keys) can be accessed here at the click of a button. 

Lesson 3 explores the topic: Are English idioms important in academic essays? Our Lesson 3 Worksheet (containing guidance, activities and answer keys) can be accessed here at the click of a button. 

To save yourself 2 Marks, click on the button below to gain unlimited access to all of our Idiomatic Phrases (Idioms) Lesson Worksheets. This All-in-1 Pack includes every lesson, activity and answer key related this topic in one handy and professional PDF.


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