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Learn how to use synonyms strategically in IELTS Writing and Speaking to avoid repetition, boost your Lexical Resource score, and impress examiners.
Toey
Examiner-informed12/09/2026
If you've ever read back through an IELTS essay draft and noticed you used the word important four times in three paragraphs, you already understand the problem this post is solving. Repetition is one of the clearest signals to an examiner that a candidate's vocabulary range is limited — and Lexical Resource, one of the four scored criteria in both Writing and Speaking, directly penalises that.
But here's the thing: synonyms aren't just a workaround for repetition. Used well, they let you express shades of meaning more precisely, control the register of your writing, and demonstrate the kind of vocabulary sophistication that separates a Band 6 response from a Band 7 or 8. In this post, I'll show you exactly how to build and apply synonym knowledge in a way that actually moves your score.
The official IELTS Writing Band Descriptors (published by Cambridge/IDP/British Council) describe a Band 7 Lexical Resource as: "uses a sufficient range of vocabulary to allow some flexibility and precision." At Band 8, the descriptor shifts to "uses a wide range of vocabulary fluently and flexibly to convey precise meaning."
Notice the progression: flexibility → precision → fluency. That's not an accident. Examiners aren't just counting how many different words you use — they're assessing whether you can choose the right word for the right context. A synonym isn't just a swap; it's a choice.
The same logic applies in Speaking. The Speaking Lexical Resource descriptor at Band 7 rewards candidates who use "less common and idiomatic vocabulary" with "some awareness of style and collocation." Repeating the same adjective throughout Part 2 or Part 3 signals to the examiner that you've hit the ceiling of your active vocabulary.
Here's the mistake I see most often: learners memorise synonym lists — big = large = enormous = vast — and then swap words in interchangeably without thinking about connotation, collocation, or register. This actually hurts the score.
Consider the word increase. Its synonyms include rise, surge, climb, grow, escalate, and soar. But these are not interchangeable:
If you look at a line graph showing a slow, steady upward trend in renewable energy usage and write "renewable energy usage soared," you've used a synonym — but you've also misrepresented the data. In Task 1, that's a Task Achievement error on top of a vocabulary misstep.
The chart shows that the proportion of households using renewable energy rose steadily from 12% in 2005 to 34% in 2020, with no sharp fluctuations.
That sentence is accurate and lexically precise. The synonym choice rose steadily matches the visual data.
Rather than memorising word lists, I recommend building what I call a contextual synonym bank — grouping synonyms by their specific usage environment rather than just their general meaning.
IELTS Writing Task 2 essays cluster around a predictable set of themes: environment, technology, education, health, urbanisation, globalisation, and crime. For each theme, identify the five to eight words you'd naturally overuse, then map out their context-specific synonyms.
For environment, the word damage appears constantly. Its context-appropriate synonyms include:
Each of those words fits a different sentence. Contaminate is wrong when you're talking about deforestation; deplete is wrong when you're describing industrial emissions. Building the bank this way forces you to think about meaning, not just form.
A synonym without its natural collocate is a liability. Native speakers don't just choose a word — they choose a word pattern. Here are three collocations built around synonyms for problem:
an acute shortage of affordable housing
a pressing concern for public health officials
a chronic issue that governments have failed to address
You can't freely swap acute, pressing, and chronic — each anchors to specific noun types and carries a distinct implication (severity, urgency, duration). When you learn a synonym, always note at least one strong collocate alongside it.
The highest-level synonym use in IELTS isn't word-for-word swapping — it's paraphrasing at the clause or idea level. This is especially critical in Reading (where you must match paraphrased question language to passage content) and in Writing Task 2 introductions (where you must restate the essay question without copying it word for word).
Suppose the Task 2 prompt reads: "Many people believe that social media has had a negative effect on society."
A weak introduction copies the prompt almost verbatim. A strong introduction paraphrases at the idea level:
It is widely argued that platforms such as Instagram and Twitter have exerted a damaging influence on communities and interpersonal relationships.
Here, many people believe becomes it is widely argued, social media becomes platforms such as Instagram and Twitter, negative effect becomes damaging influence, and society becomes communities and interpersonal relationships. That's four synonym-level substitutions, all accurate, all natural.
Speaking is where synonym knowledge gets tricky, because you can't pause and consult a mental thesaurus mid-sentence. The goal isn't to perform vocabulary — it's to have enough range that variety emerges naturally.
In Part 3, where you're expected to discuss abstract ideas, examiners specifically listen for less common vocabulary and flexible expression. Here's how synonym fluency sounds in practice:
Q: Do you think governments should do more to protect the environment?
A: Absolutely — I think there's a real obligation there. Governments have the regulatory power and the financial resources to enforce meaningful change, and frankly, voluntary action by individuals, while admirable, isn't going to be sufficient on its own. The scale of environmental degradation we're seeing — habitat loss, ocean acidification, air contamination — demands coordinated, top-down intervention.
Notice that environmental damage never appears once. Instead: environmental degradation, habitat loss, ocean acidification, air contamination. Each is a context-specific synonym cluster that signals genuine vocabulary depth — not a memorised list being recited.
1. Forced formality in the wrong context. If a Speaking Part 1 question asks where you grew up, you don't need to say "the municipality in which I was raised." Synonyms should match register. Formal vocabulary in casual conversation sounds unnatural and can actually lower your score.
2. Synonyms that change the meaning. Famous and notorious are not interchangeable — notorious implies a negative reputation. Slim and thin carry different connotations in British English. Always verify meaning, not just definition.
3. Over-relying on high-frequency "impressive" words. Words like plethora, myriad, or pivotal appear so often in IELTS essays that examiners recognise them as learned phrases rather than evidence of genuine range. A precise, well-collocated common word often scores better than a showy rare one used awkwardly.
I want to give you something concrete, not vague advice about "reading widely." Here's a focused weekly approach:
This isn't about volume — it's about depth of processing. You'll retain contextual synonym knowledge far better by using it in production than by reading a list.
Synonyms aren't decoration. In IELTS, they're evidence — evidence that you have the vocabulary range to express ideas with flexibility and precision across a range of contexts. The examiners aren't looking for a thesaurus; they're looking for a writer and speaker who chooses words intentionally.
Build your synonym bank by topic, learn collocations alongside meanings, and practise paraphrasing at the idea level rather than the word level. Do that consistently, and you'll find that Lexical Resource stops being a weak point and starts being one of your strongest.
Yes — directly. Lexical Resource is one of four equally weighted criteria in both IELTS Writing and Speaking. The Band 7 descriptor explicitly rewards 'flexibility and precision' in word choice, and the Band 8 descriptor rewards 'fluent and flexible' use of a wide vocabulary range. Using context-appropriate synonyms demonstrates exactly that flexibility.
Only if you verify the synonym in context. A thesaurus gives you options, not guarantees. Words like 'notorious' and 'famous' appear as synonyms in a thesaurus but carry very different connotations. Always check a synonym's meaning and natural collocations in a learner's dictionary before using it in your essay.
Quality over quantity. For each high-frequency word in a topic area, knowing two or three context-specific synonyms with their correct collocations is far more useful than a list of ten words you can't use accurately. Focus on the words you personally overuse most — those are your highest-value targets.
Absolutely — and this is essential. IELTS Reading questions almost always paraphrase the language used in the passage. Recognising that 'a significant rise' in the question maps to 'a marked increase' in the passage, for example, is the core skill for matching and True/False/Not Given tasks. Training your synonym recognition directly improves your Reading score.
Not always. IELTS Writing Task 2 rewards formal, academic vocabulary, while Speaking — especially Part 1 — rewards natural, conversational language. A synonym like 'municipality' suits a formal essay but sounds unnatural in casual spoken English. Match your synonym choice to the register of the task.
Toey
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