Should you use idioms to get a higher IELTS score? Not necessarily.
If you have been told that you need to use lots of idioms to get Band 7 or 8, you may be tempted to memorise lists such as over the moon, a piece of cake, raining cats and dogs and every cloud has a silver lining.
It’s usually better to avoid this approach.
Idioms can be useful in IELTS, particularly in the Speaking test, but using an idiom just because you think it will make you sound more advanced can actually make your English sound unnatural.
The aim is not to use as many idioms as possible.
The aim is to use vocabulary that is accurate, appropriate, natural and flexible.
What does IELTS actually say about idioms?
Idiomatic language is part of Lexical Resource, the vocabulary criterion used to assess IELTS Speaking and Writing.
For example, the Band 7 Speaking descriptor says that a candidate:
“uses some less common and idiomatic vocabulary”
But notice the word some.
This does not mean that you need to fill your answers with idioms.
IELTS examiners are looking at your vocabulary as a whole. They consider things such as:
- the range of vocabulary you use
- whether your word choices are accurate
- whether they are appropriate for the situation
- whether you use collocations naturally
- whether you can express your meaning precisely
- whether you can paraphrase when you do not know a particular word
- how accurately you use less common and idiomatic language
So one natural idiom is much better than five memorised idioms that sound forced or are used incorrectly.
So, should you use idioms in IELTS?
✅ Yes, if you can use them naturally.
❌ No, if you are using them simply to impress the examiner.
That’s the most important rule.
If you have heard an expression many times, understand exactly what it means, know how it fits into a sentence and feel comfortable using it, then it may be a useful part of your vocabulary.
But if you have memorised a list of “Band 9 idioms” and are trying to squeeze them into your Speaking answers, don’t.
This is one of the biggest problems I see with IELTS vocabulary advice online.
Students are often given lists of impressive-sounding expressions and told to use them in the test. The result can be vocabulary that is technically correct but sounds unnatural.
And remember: IELTS is not a vocabulary competition.
The problem with memorising idioms
An idiom is an expression whose meaning is not simply the sum of the individual words.
For example:
I’m over the moon.
This means I’m extremely happy, not that you are physically above the moon.
The problem is that knowing the meaning of an idiom is only part of knowing the idiom.
You also need to know:
- what it means
- how to use it grammatically
- which words go with it
- whether it is formal or informal
- who normally uses it
- whether it is common or old-fashioned
- whether it is normally spoken or written
- what kind of situation it suits
- whether it sounds natural in your particular sentence
That’s a lot to think about in an IELTS Speaking test!
1. Accuracy matters
Idioms are often fixed expressions, so changing one word can make them sound wrong.
For example:
❌ I passed with a flying colour.
✅ I passed with flying colours.
❌ I got a cold foot.
✅ I got cold feet.
❌ I’m on nine clouds.
✅ I’m on cloud nine.
❌ I have some time on my hand.
✅ I have some time on my hands.
These mistakes are funny when you see them written down, but they can also make your English sound less natural.
If you are not completely sure how an expression works, use a simpler expression that you know you can use correctly.
2. The context matters
An idiom can be perfectly accurate but still sound strange in a particular situation.
For example:
I feel over the moon when I go to the supermarket.
The speaker probably means that they enjoy going to the supermarket.
But over the moon means extremely happy, so it does not really express that idea.
A better choice might be:
I actually quite enjoy going to the supermarket.
Or:
I really like going there.
The second examples are not “advanced” vocabulary.
But they are natural and accurate.
And that is much more important.
3. Register matters
The words and expressions you use with friends may be different from the language you use when speaking to someone you don’t know well.
This is called register, but you don’t need to remember the term. What matters is knowing whether an expression sounds formal, informal or natural for the situation.
Some expressions are very informal.
Some are old-fashioned, humorous or strongly associated with particular groups of speakers.
This is particularly important in IELTS Writing. An expression that sounds perfectly natural in a conversation may be too informal for an Academic Writing Task 2 essay.
For example:
❌ Every cloud has a silver lining, so we should look on the bright side of climate change.
✅ Despite these challenges, climate change policies can also have some positive effects.
The first sentence isn’t grammatically wrong. The problem is that the idiom sounds too conversational for this type of academic essay.
4. Some expressions are much more useful than others
Instead of memorising hundreds of idioms, learn expressions that you are actually likely to use.
For example, in Speaking, these can be useful:
get the hang of something
= become able to do something successfully
It took me a while to get the hang of driving in the UK.
have a go at something
= try something
I’ve never tried skiing before, but I’d love to have a go.
be a big fan of something
= like something very much
I’m a big fan of live music.
not be my thing
= not be something you particularly like
Camping isn’t really my thing.
These are useful because they are relatively natural, common expressions that can fit into everyday conversation.
But you still need to make sure they fit your meaning and the situation.
Idiomatic language vs idioms
When IELTS talks about idiomatic language, this does not mean that you need to learn lots of traditional idioms such as over the moon or raining cats and dogs.
Natural English contains many other expressions that can show a good range of vocabulary, including collocations, phrasal verbs, fixed expressions and common phrases, including:
- collocations
- phrasal verbs
- common chunks
- fixed expressions
- conversational phrases
- idioms
For example:
- make a decision
- take responsibility
- have a go
- get the hang of something
- a close friend
- highly unlikely
These may not look as impressive as every cloud has a silver lining, but they are extremely useful because they help you produce natural English.
In fact, learning collocations and useful chunks is often a much better investment of your study time than memorising long lists of idioms.
What should you do instead?
Rather than learning a list called “50 idioms for IELTS”, try this:
1. Listen to real English
Pay attention to expressions that people actually use.
You might hear them in:
- podcasts
- interviews
- films and TV programmes
- YouTube videos
- conversations
- news programmes
- lectures
If you hear an expression repeatedly, investigate it.
Ask yourself:
- What does it mean?
- How is it used?
- Is it formal or informal?
- Who uses it?
- What words normally go with it?
- Would I actually use this expression?
2. Check the expression in a good dictionary
Don’t rely on a random “IELTS idioms” website.
Use a reliable learner’s dictionary such as Cambridge, Oxford or Longman.
Look at the example sentences as well as the definition.
You want to know how the expression is actually used, not just what it means.
3. Learn the whole expression
Don’t just learn:
cold feet = nervous
Learn:
get cold feet = suddenly become too frightened to do something
Then notice how it works in a sentence:
I was going to apply for the job, but I got cold feet at the last minute.
This gives you much more useful knowledge than a simple translation.
4. Use it when it genuinely fits
Don’t start with the idiom. Start with your idea.
Then ask:
Is there a natural expression that would help me express this idea?
If there is, use it.
If there isn’t, use ordinary vocabulary.
You do not get extra marks simply for making your English sound complicated.
🗣️ What about IELTS Speaking?
This is where idiomatic language is most useful.
Speaking is an informal, spontaneous interaction, so natural everyday expressions can fit very well.
For example:
Question: Do you enjoy cooking?
Yes, I’m quite keen on cooking. I find it really relaxing, especially at the weekend.
You don’t need to say:
❌ Cooking is my cup of tea because I am over the moon whenever I am in the kitchen.
The second answer contains more “idioms”, but that does not make it better.
It sounds much more like someone who has memorised a list.
The first answer is simple, natural and appropriate.
✍️ What about IELTS Writing?
This is where you need to be more careful.
In Academic Writing Task 2, you are writing a formal essay, so conversational idioms are usually inappropriate.
For example:
❌ Every cloud has a silver lining, so governments should look on the bright side of technological development.
A more appropriate version would be:
✅ Despite these disadvantages, technological development can also provide significant benefits.
However, this does not mean that every idiomatic expression is forbidden in academic writing.
IELTS assesses whether your vocabulary is appropriate for the task and context, including your use of collocations, idiomatic expressions and sophisticated phrasing.
The important question is therefore not:
“Is this an idiom?”
but:
“Is this the right expression for this context?”
For example, an expression such as play a crucial role is perfectly natural in academic writing:
Education plays a crucial role in reducing social inequality.
You don’t need to avoid an expression simply because it is a fixed expression
What about General Training Task 1?
This is different because the style of your letter depends on who you are writing to.
An informal letter can contain natural conversational language and, if appropriate, an idiomatic expression or two.
For example:
I’ve never been kayaking before, but I’d love to have a go.
That sounds much more natural in an informal letter than an overly formal alternative.
But you still don’t need to fill the letter with idioms.
The aim is to sound naturally informal, not artificially “idiomatic”.
My rule for IELTS idioms
Here’s the rule I recommend:
Don’t learn an idiom because someone tells you it will get you Band 7. Learn it because you have heard it, understand it, and know how to use it naturally.
And if you are not sure whether an expression is appropriate, don’t use it.
A simple expression that communicates your meaning accurately is always better than an impressive expression that you have used incorrectly.
Remember: vocabulary is about choice
The best IELTS vocabulary is not necessarily the most difficult vocabulary.
Good vocabulary means being able to choose the right word or expression for the situation.
Compare:
I was over the moon when I got the job.
with:
I was absolutely delighted when I got the job.
Both are good.
The first is more conversational.
The second is slightly more neutral.
Neither is automatically “better”.
Your job is to choose the one that fits your meaning, your style and the situation.
That’s what good vocabulary is really about.
A final warning about “Band 9 idioms”
If you see a website offering:
“50 essential Band 9 idioms for IELTS”
be careful.
There is no official list of “Band 9 idioms”.
You do not need to memorise a particular set of expressions to get a high score.
In fact, IELTS research has found that higher-proficiency speakers can demonstrate sophisticated vocabulary through fluent use of formulaic expressions, including expressions made up of very common words.
So don’t waste your time trying to sound impressive.
Listen to good English. Notice useful expressions. Check how they are used. Then use them when they genuinely fit.
That’s a much better way to develop your IELTS vocabulary.
About Fiona
Fiona is an IELTS trainer, ex-examiner and course creator based in the UK. She has a Master’s in Teaching English as a Foreign Language (Distinction) and over 35 years of teaching experience. She has helped thousands of IELTS candidates develop the language and exam skills needed to achieve their target scores.
Idioms are not completely banned from Writing Task 2 (“On the other hand” is an idiom).
Here’s a nice a example where one of my Members uses the idiom ‘packed like sardines’ (= uncomfortably close together).
Normally I would not recommend using idioms in formal, academic essays, but remember that writing for IELTS is not the same as writing for publication or for an academic assignment at university.
The purpose of writing for IELTS is ALWAYS to demonstrate your ability to make the right language choices using a wide range of vocabulary.
So the idiom ‘packed like sardines’ is perfect here – it sums up the experience of the average commuter being forced to use over-priced and under-funded transport systems!
https://app.getbeamer.com/ieltswithfiona/en/everyday-idioms-packed-like-sardines
Very much appreciated your efforts. This will greatly help us enrich our IELTS Vocabulary.
Thanks for visiting my site Rajib,
Best wishes
Fiona