Vocabulary in IELTS Speaking: Should You Use Idioms?
Neha from Chandigarh said it was “raining cats and dogs” while describing a sunny trip to Shimla. The idiom was real; using it there wasn’t.
You don’t need to fill your answers with idioms in IELTS Speaking, but the Band 7 Lexical Resource descriptor does mention idiomatic items. What helps is precise, natural vocabulary, some less common words, idiomatic phrases used correctly, and the ability to paraphrase when a word escapes you.
Practice question: What do you usually do at weekends?
What the Lexical Resource Descriptors Say
The official key assessment criteria ask about the variety of words you use and whether they suit the meaning, style and collocation (word partnership), including idiomatic expressions. They also list the ability to paraphrase, which means getting round a vocabulary gap with other words.
At Band 6, the vocabulary is enough to discuss topics at length. It may sometimes be inappropriate, but the meaning is clear, and the candidate can generally paraphrase.
At Band 7, vocabulary is used flexibly across a variety of topics. The descriptor mentions some ability to use less common and idiomatic items, with awareness of style and collocation, though inappropriate choices still occur, plus effective paraphrase. For the other criteria, see our Band 5 versus Band 7 guide.
What “Idiomatic” Can Mean in Practice
The descriptors don’t define “idiomatic”. For most learners, natural collocations and phrasal verbs are a safer route to sounding idiomatic than proverb-style idioms. “Catch up with friends” and “make a decision” are examples.
The table pairs idioms that are easy to force into an answer with plainer options.
| ❌ Forced idiom | ✅ Natural alternative | Why |
|---|---|---|
| Burning the midnight oil | Studying late at night | Plain words say exactly what you did |
| Once in a blue moon | Very rarely | Dropped into every answer, it sounds rehearsed |
| At the drop of a hat | Straight away | The plain adverb is clearer under pressure |
| Hit the nail on the head | You’re exactly right | The direct phrase is quicker to say |
| Bite the bullet | Face it and get on with it | Say what the situation actually was |
To build natural word partnerships, see our guide to collocations for natural English. You can also study common phrasal verbs. If you want to learn idioms properly, our lesson on common English idioms gives meanings and examples.
Paraphrasing When You Forget a Word
Even fluent speakers forget words. Describing the thing is a skill the criteria name, so you don’t need to freeze.
Suppose you can’t remember “pressure cooker” in Part 2. Say “a pot with a tight lid that cooks lentils quickly using steam” and carry on.
Sample Answer: Natural Vocabulary in Action
Here is an illustrative answer to the practice question that uses collocations and phrasal verbs instead of proverbs.
Sample answer (illustrative Band 7)
On weekends, I like to take it easy and unwind after a busy week at work. Saturday mornings usually involve catching up on sleep and having a relaxed breakfast with my flatmates. Later in the afternoon, I often run a few errands or head to a local café to read. Occasionally, I meet up with college friends for dinner, but I mostly prefer staying in to recharge.
Natural phrases used in this sample:
- Phrasal verbs: “catch up on”, “head to”, “meet up with”
- Collocations: “take it easy”, “a busy week at work”, “run errands”, “have a relaxed breakfast”
Incorrect: “Cracking IELTS was a piece of cake.”
Correct: “Preparing for IELTS took more effort than I expected, but studying every evening helped.”
Incorrect: “It was raining cats and dogs when we reached Shimla.”
Correct: “It was a bright, sunny day in Shimla, so we spent the afternoon walking along the Mall.”
Tip
Learn vocabulary in natural chunks such as “make a living” or “heavy traffic”, rather than as isolated words from a list of idioms.
Try It
Rewrite each sentence by replacing the forced idiom with natural phrasing.
- “Passing my driving test was a walk in the park.”
- “This phone costs an arm and a leg.”
- “When I heard the exam results, I was on cloud nine.”
Show sample answer
- Passing my driving test was surprisingly straightforward.
- This phone is far too expensive for what it offers.
- When I heard my results, I was delighted and relieved.
Key Takeaways
- Band 7 mentions some less common and idiomatic items, with awareness of style and collocation.
- An idiom that doesn’t fit the situation sounds odd, as Neha’s did.
- Phrasal verbs and natural collocations are a safer route to idiomatic English.
- When you forget a word, describe what it does.
The bottom line: Use an idiom only when it fits what you actually mean, and let precise everyday vocabulary carry the rest.