Vocabulary
Where they earn marks, where they cost them, and twelve worth knowing. With a practice exercise.
Phrasal verbs and idioms in IELTS are useful in one paper and damaging in another. In the speaking test they signal natural, flexible English. In Task 2 writing they signal an informal register, and that costs marks under Lexical Resource.
The distinction is not about difficulty. It is about where the language belongs. A candidate who uses put off in a formal essay and postpone in casual conversation has both of them the wrong way round.
Where they belong
Six situations, and the two where they lower your band.
Ideal. Informal, natural language is exactly what this part is for, and phrasal verbs make you sound like a speaker rather than a reciter.
Use with care. The discussion is more abstract and slightly more formal, so one or two well-placed idioms work and a stream of them does not.
Correct. A letter to a friend should sound like one, and formal single-word verbs would be the error here.
Avoid the informal ones. Postpone rather than put off, discover rather than find out, deteriorate rather than get worse.
Same as Task 2. A complaint to a company written with casual phrasal verbs reads as the wrong register.
An idiom used slightly wrongly is more noticeable than a plain word used correctly, and examiners hear memorised idioms constantly.
Method
All of these appear in ordinary conversation. Each is given with its meaning.
Stay focused on what matters. Draw the line — refuse to accept something beyond a certain point.
Form an opinion from appearances alone. Toe the line — follow the rules, often reluctantly.
A rough estimate. A catch-22 — a situation where the solution is prevented by the problem itself.
Release stress or frustration. Pass the buck — avoid responsibility by giving it to someone else.
Argue a position you do not hold, to test it. Sit on the fence — refuse to take a side.
Join something because it has become popular. Your guess is as good as mine — I do not know either.
Practice
Choose the option that completes each sentence.
Read the whole sentence, including what comes after the gap.
Idioms are fixed, so the wrong one will usually clash with the rest of the sentence rather than merely sounding odd.
1The mistake happened because of a lack of care. If he had ______, everything would have been fine.
Kept his eye on the ball. It means stayed focused. Drawing the line is about refusing to accept something, which does not fit a mistake caused by carelessness.
2He had little money himself, yet he handed in the wallet. It shows you should never ______.
Judge a book by its cover. The sentence contrasts appearance with behaviour, which is exactly what the idiom describes.
3He took no responsibility for his errors and simply wanted to ______.
Pass the buck. Avoiding responsibility by handing it to someone else. Toeing the line means following the rules.
4I cannot give exact costs yet, but as a ______ it will be around forty thousand.
Ballpark figure. A rough estimate. A catch-22 is a situation where the problem prevents its own solution.
5You have been working very hard. It is fine to ______ every now and then.
Let off steam. Releasing stress. The second option is about reaching a decision, which does not fit.
6You are writing a Task 2 essay and want to say a decision was delayed. Which is better?
Postponed. Task 2 is a formal essay, so the single-word verb is correct. Put off would be right in speaking or an informal letter.
Use it in speaking and leave it out of Task 2. That single rule prevents most of the register errors idioms cause.
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Recognising an idiom is easier than using one naturally, and a memorised idiom in the wrong place is worse than none at all.
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Not in Task 2 or a formal letter. Idioms are informal, and using them lowers your band for register. They belong in the speaking test.
In formal writing, the informal ones do. In speaking they raise it, because they show natural flexible English.
A small number used naturally beats a long list used stiffly. Ten or twelve you genuinely understand is plenty.
Only if they fit. Examiners hear memorised idioms constantly, and one dropped into the wrong place is more noticeable than plain language.
Idioms and informal phrasal verbs in speaking and informal letters. Single-word formal verbs in Task 2 and formal letters.
Full membership
There is no rule about how many idioms is too many. It is a judgement, made by an examiner, about whether your language fits the situation.
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