I've watched this happen hundreds of times. A student sits down for their IELTS Speaking test, nervous energy pumping through their veins, and they decide it's the perfect moment to showcase every idiom they've memorized in the past three weeks. "I'll let the cat out of the bag," they say about a secret. "We need to think outside the box," they offer about problem-solving. "That's the tip of the iceberg," they add about climate change.
The examiner nods politely. But here's what's really happening: the student just lost 2-3 band points.
Why? Because using idioms in IELTS Speaking isn't about cramming in as many as possible. It's about sounding natural, fluent, and confident. And let me be blunt: most students get this wrong.
The IELTS Speaking assessment focuses on four criteria: Fluency & Coherence, Lexical Resource (vocabulary), Grammatical Range & Accuracy, and Pronunciation. Notice something? There's no separate box for "Idiom Accuracy." Idioms fall under Lexical Resource, which means they're one tool among many in your vocabulary toolkit, not the entire toolkit.
An examiner isn't sitting there thinking, "How many idioms did this candidate use?" They're thinking, "Does this person sound like someone who naturally uses English?" That's the difference.
Native speakers use idioms, yes. But they use them strategically. They use them when they naturally fit. They don't force them into sentences where they don't belong. That's exactly what you need to do.
Weak: "When I think about my future career, I need to think outside the box and break the ice with new opportunities because I don't want to put all my eggs in one basket."
Good: "I'm interested in trying something different with my career. Rather than following the traditional path, I want to explore areas where I can actually make a difference."
The weak example uses four idioms in one response. It sounds forced. The good example uses zero idioms but sounds fluent, natural, and confident. That's band 7+ material.
In a 12-15 minute IELTS Speaking test, aim for roughly 3-8 idioms spread across all three parts. That's naturally spaced, not forced. Each idiom should only appear when it actually serves a purpose and fits how you'd normally express that idea.
But here's the catch: those idioms should only appear when they actually serve a purpose. They shouldn't be decorations. They should be part of how you naturally express an idea.
Let's say the examiner asks: "What kind of person do you admire?" A weak approach injects idioms randomly.
Weak: "I admire people who are a breath of fresh air in society. They have their head in the clouds, and they're always thinking outside the box. I think they really go the extra mile."
Notice how "have their head in the clouds" doesn't even fit the meaning? The candidate knew it was an idiom and threw it in anyway.
Good: "I admire people who are willing to take risks and think creatively. I really respect someone who goes the extra mile to help others, even when it's difficult. Those kinds of people inspire me."
This response uses one well-placed idiom ("go the extra mile") that fits naturally into the sentence. The rest of the answer flows smoothly without forcing vocabulary.
Tip: If you have to pause to remember an idiom, don't use it in the actual test. You'll lose fluency points while you're searching for the words. Save it for when it comes naturally.
I see students with lists of 50+ IELTS idioms they've memorized. That's not the strategy.
Instead, choose 8-10 idioms that fit the topics you're likely to discuss: work, family, hobbies, education, technology, travel, culture. Learn them so well that you could use them in conversation without thinking. That's the difference between knowing an idiom and owning it.
Here are idioms that actually work in IELTS Speaking topics:
Now, here's what most students don't do: they don't practice using these in realistic speaking scenarios. Pick one topic. Pick one idiom. Record yourself speaking for 2 minutes using that idiom naturally. Do this 3-4 times per idiom, and you'll actually own them.
Let me walk you through the actual errors I see in students' practice tests.
Mistake 1: Using an idiom in the wrong context. A student once told me, "Learning English is a piece of cake for me." Technically grammatically correct, but then they spent the rest of the test struggling with complex sentences. The idiom contradicted their actual performance, and the examiner noticed.
Mistake 2: Mispronouncing or misusing the idiom. I've heard students say "a breath of sunshine" instead of "a breath of fresh air." Once an idiom is broken, it's not an idiom anymore. It's just confusing.
Mistake 3: Pausing to remember the idiom mid-sentence. You know that moment when someone says something like, "I really... um... I really go the, uh... the extra... mile... in my work." That hesitation costs you fluency points. If you're not 100% confident, skip it and use simpler vocabulary instead.
Tip: Practice your idioms out loud, multiple times, until they flow as naturally as your native language. If you ever stumble, remove that idiom from your IELTS toolkit and replace it with another one.
Here's something different from every other IELTS blog you'll read. Don't just memorize a list of idioms. Instead, think about your own life, your own interests, your own stories. What idioms would you actually use to describe your experience?
Do you enjoy gaming? You might naturally say something "takes too much time" or "is addictive." That's simpler than forcing in "playing with fire." Do you like cooking? You might say you "enjoy the challenge" or "love experimenting." These are more authentic than hunting for idioms that don't reflect who you are.
The best IELTS Speaking performance sounds like a real conversation, not a vocabulary show. When the examiner asks you about your hobby and you respond with language that actually comes from your personality and experience, you sound fluent. You sound natural. You sound like a Band 7 or Band 8 speaker.
Here's an example from an actual IELTS Part 1 question about hobbies.
Weak: "My hobby is reading. I really think books are a breath of fresh air in modern society. I enjoy getting my nose in a book and hitting the books whenever I have time. Reading is the way to go."
Good: "I'm really into reading, especially science fiction and crime novels. There's something about getting completely absorbed in a story that helps me relax after a stressful day. I usually read for about an hour before bed."
The good example has no idioms. It's specific. It's personal. It's fluent. The weak example sounds like it came from a textbook.
Before you use an idiom in your actual IELTS test, ask yourself these three questions:
If you answer no to any of these questions, use simpler vocabulary instead. Band 7 speakers don't use complex language for the sake of it. They use it when it serves a purpose.
I've talked to IELTS examiners at training seminars, and here's what they've told me. They don't expect idioms. They don't count them. They notice them only if they sound natural or if they sound forced. A candidate who uses zero idioms but speaks fluently, clearly, and with a wide range of vocabulary will score the same as a candidate who uses five idioms awkwardly.
The key phrase is "fluency and coherence." That means your ideas flow. Your words connect. Your speech doesn't sound like you're pulling from a script.
In fact, I've seen candidates score Band 8 on IELTS Speaking without using a single recognizable idiom. How? By speaking naturally about their life, using varied sentence structures, and maintaining clear pronunciation.
So here's my honest advice: use idioms if they help you sound more natural. Don't use them if they're a distraction. The examiner is listening to whether you sound like someone who's actually lived in an English-speaking environment or studied English seriously. Idioms are just one way to show that. They're not the only way. Check out our guide on IELTS Speaking practice to work on the broader techniques that matter more.
Here's something most teachers don't tell you. Many students think they need idioms to sound advanced. But that's wrong. What you actually need is control over your speech.
If you're using filler words like "um," "uh," "like," "you know" every few seconds, then adding an idiom won't help. You'll just sound like someone who's forcing advanced vocabulary while struggling with basic fluency. The fundamentals come first, idioms second.
Here's what your actual test approach should look like.
Part 1 (4-5 minutes): Use 0-2 idioms. These questions are simple and personal. Your job is to answer naturally and show clear pronunciation. Idioms feel forced in Part 1.
Part 2 (1-2 minutes preparation, 1-2 minutes speaking): Use 1-2 idioms. You've got time to prepare, so pick one or two that fit your cue card topic naturally. Write them down during prep time so you don't fumble during delivery.
Part 3 (4-5 minutes): Use 2-4 idioms. These are abstract questions that allow more complex vocabulary. This is where idioms can actually shine because the questions naturally call for more sophisticated answers.
That's 3-8 idioms across the entire test. Not 15. Not 20. Just enough to show lexical range without sounding robotic. When you're preparing for Part 2, make sure you structure your notes clearly so you can reference them easily without breaking your flow.
Here's the only practice method that works for idioms. Pick a Part 1 question. Answer it out loud without planning. Record yourself. Play it back.
Did an idiom come up naturally? Good. Did you force one in? Cut it. Did you hesitate? Remove that idiom from your list.
Do this five times with different questions. You'll quickly see which idioms fit how you actually speak and which ones you're just memorizing. Use our band score calculator to track your progress across multiple practice sessions and identify patterns in where you're scoring well and where you need work.