Lexical Resource: Why a Bigger Vocabulary Is Not the Answer

A common way to prepare for this criterion is a list of fifty impressive words, learned by heart. The band descriptors show where that leads.

At band 6, a writer who takes risks uses "a wider range of vocabulary", but with "higher degrees of inaccuracy or inappropriacy" source: ielts.org. So a wider range does not raise the band unless you control it.

This guide is part of our series on the four Writing criteria. The hub is How IELTS Writing Is Marked, and the previous part covered coherence and cohesion.

Lexical resource is marked in both Writing tasks source: ielts.org. Speaking has a criterion with the same name source: ielts.org.

So good control of vocabulary helps you in Writing and in Speaking. Our guide to lexical resource in Speaking covers the spoken version.

What lexical resource measures

The criterion looks at the range of words you use, including synonyms that avoid repetition. It looks at whether your words suit the topic, and how precise your word choice is.

It also covers collocations and idiomatic expressions. Finally, it covers errors in spelling and word formation: how many there are, and what effect they have on your meaning source: ielts.org.

A collocation is a pair of words that naturally go together. Two points in that list are easy to miss. First, spelling has no criterion of its own in Writing, so it is marked here. Second, an error is judged by its effect. An error that hides your meaning costs more than one the reader hardly notices.

The ladder from band 5 to band 9

In the Task 2 band descriptors, spelling and word formation appear at every band. Precision appears from band 6 upwards, from "a lack of precision" to "precise meanings" at band 8.

source: ielts.org

What changes from band 6 to band 7

At band 6, the meaning is generally clear despite "a rather restricted range or a lack of precision in word choice". At band 7, there is "some ability to use less common and/or idiomatic items", and "an awareness of style and collocation is evident" source: ielts.org.

Two things change. The first is precision: the word that says exactly what you mean. The second is collocation. For example, English says "make a decision", not "do a decision", and "heavy rain", not "strong rain".

A less common word helps only when you use it accurately and naturally. Used wrongly, it counts against you.

Here is one sentence written two ways, for this page.

Nowadays, the usage of automobiles^{note 1} has increased, and this makes serious harm^{note 2} to the environment.

Car use has risen sharply^{note 3} in most cities, and the extra traffic causes serious harm^{note 4} to the air we breathe.

1. "The usage of automobiles" tries to sound advanced and sounds unnatural instead. This is the band 6 risk-taker from the top of this page: a wider range, but less accurate.
2. This is a collocation error. English speakers cause harm or do harm. Nobody makes harm.
3. "Risen sharply" is a common pair for a change in numbers. It is also more precise than "increased", because it says how fast the change was.
4. At band 7, "an awareness of style and collocation is evident" source: ielts.org. "Cause harm" is the pair a reader expects.

The second version uses no rare words. It shows the other thing band 7 asks for, control of collocation, and its meaning is exact.

How to improve your vocabulary for IELTS Writing

Learn words in pairs

Learn verbs with the nouns they go with, and adjectives with their nouns. Keep a notebook of these pairs, not of single words. A list of single words builds the wider but less accurate range that band 6 describes.

Learn words for broad topics

General Training Task 2 is on a topic of general interest source: ielts.org.

On either test, build precise words for broad areas such as education, work, technology, the environment and health. A word you can use well is worth more than a rare one you never use.

Keep a spelling log

You probably misspell the same few words again and again. Write down each word you get wrong, and practise it until you spell it correctly without thinking.

Avoid memorised phrases

At band 4, there may be inappropriate use of memorised phrases and formulaic language source: ielts.org.

A sentence that could open any essay tells the examiner nothing about your vocabulary. Write sentences about the question in front of you.

IELTS paraphrasing shows how to rewrite the Task 1 opening.

How much it counts

The four Writing criteria are weighted equally, and each task is assessed on its own source: ielts.org. So lexical resource is a quarter of the mark for each task.

Next in the series: grammatical range and accuracy, where correct sentences matter more than difficult ones. For a plan across all four criteria, see our Writing improvement plan.

The public Writing band descriptors and key assessment criteria are published on ielts.org. The equal weighting of the criteria and the Speaking criteria are on IELTS scoring in detail, and the General Training Task 2 topics on the General Training Writing format page. Descriptors updated May 2023. Last checked on 27 September 2026. The example sentences were written for this page and are not from any test.