IELTS Academic Writing

IELTS Writing Task 1 Line Graph: Structure, Vocabulary & Example

Learn how to analyse a line graph quickly, write a clear overview and organise the most important trends without turning your answer into a list of numbers.

Published August 18, 2026 · 10 min read

What IELTS Task 1 actually requires

In IELTS Academic Writing Task 1, you may be given a graph, table, chart or diagram. IELTS says you should write at least 150 words in about 20 minutes. Your job is to summarise the information by selecting the main features and making comparisons where relevant, not to describe every single data point.

For line graphs, the key skill is recognising movement over time: increases, decreases, fluctuations, plateaus, peaks, troughs and crossovers.

A reliable 4-paragraph structure

1. Introduction

Paraphrase what the graph shows: what is measured, where, and over what time period.

2. Overview

Summarise the biggest patterns in one or two sentences. Mention the dominant rise/fall, highest or lowest series, major crossover, or the most striking contrast. Avoid filling the overview with detailed numbers.

3. Body paragraph 1

Group related trends and support them with selected figures.

4. Body paragraph 2

Describe the remaining major trends and make useful comparisons.

How to write a strong overview

Official IELTS preparation guidance emphasises selecting key features and presenting an overview. Before writing, ask: Which line changed the most? Which ended highest? Did any lines cross? Was there a clear peak or low point? Did one series stay stable while another moved sharply?

A weak overview repeats the title. A strong overview tells the reader what happened overall.

Useful line graph vocabulary

Upward movement

rose, increased, climbed, grew, reached a peak of

Downward movement

fell, decreased, declined, dropped, reached a low of

Stable / mixed

remained stable, levelled off, fluctuated, recovered

Degree

slightly, gradually, steadily, sharply, dramatically

Use vocabulary accurately rather than forcing rare words into every sentence.

Original IELTS-style worked example

Practice prompt

The line graph shows the percentage of commuters using public transport in three cities from 2005 to 2025. City A rises from 28% to 52%, City B falls from 45% to 34%, and City C increases from 30% to 48%, with City C briefly overtaking City A in 2015.

Sample overview

Overall, public transport use increased substantially in Cities A and C, while City B experienced a gradual decline. By the end of the period, City A recorded the highest proportion, despite being temporarily overtaken by City C midway through the timeframe.

Why this works

It identifies the two main directions, the final highest city and the crossover. It does not waste the overview on minor figures.

Common mistakes that lower Task 1 performance

  • Describing every year or number instead of selecting key features.
  • Writing no clear overview.
  • Giving reasons or opinions that are not shown in the visual.
  • Using trend vocabulary inaccurately.
  • Spending too long on Task 1 and reducing the time available for Task 2, which contributes twice as much to the Writing score.

A 20-minute practice routine

  1. Spend 2 minutes identifying the largest trends and grouping the lines.
  2. Spend 2 minutes planning the introduction and overview.
  3. Spend about 13 minutes writing the two body paragraphs.
  4. Use the final 3 minutes to check figures, grammar, spelling and comparisons.

Practise this under computer-test conditions so planning, typing and checking become automatic.

Move from strategy to timed practice

Use CBI Prep to practise IELTS Writing on computer, then complete a full mock without pausing or using outside tools.

Related guides

Frequently asked questions

How long should I spend on IELTS Writing Task 1?

IELTS recommends about 20 minutes for Academic Writing Task 1. You must write at least 150 words.

Do I need an overview for a line graph?

Yes. Official IELTS guidance says a clear overview of the main trends or changes is important for Task Achievement and is necessary for stronger band performance.

Should I describe every number on the graph?

No. The task asks you to select and report the main features and make relevant comparisons. Focus on the most important trends, peaks, falls, crossovers and contrasts.

Can I give my opinion in Task 1?

No. Report the visual information objectively. Do not explain causes unless the visual itself provides that information.

Official references