IELTS Writing Task 1: Line Graph
Line graphs are the most common visual in IELTS Academic Writing Task 1. They show how data changes over time, and your job is to describe the key trends, comparisons and significant data points in at least 150 words.
This guide covers the exact structure you should follow, essential vocabulary for describing trends, and three complete sample answers with examiner-style comments to help you reach Band 7 and above.
How to Approach a Line Graph Question
When you see a line graph in Task 1, spend 2-3 minutes analysing it before you write. Follow these steps:
Read the Question Carefully
Identify what the graph shows (the subject), the units of measurement, the time period, and the categories being compared. The question wording often tells you exactly what to summarise.
Identify the Main Trends
Look at the overall direction of each line. Is it going up, down, or staying flat? Which line is highest at the start and end? Are there any crossover points where one line overtakes another?
Note Key Data Points
Write down starting values, ending values, peaks (highest points), troughs (lowest points), and any significant changes. You will use these numbers in your body paragraphs.
Group Your Information
Decide how to split the data into body paragraphs. You might group lines that increase together vs. lines that decrease, or split the time period into two halves.
Step-by-Step Structure
A well-structured line graph response has four parts. This structure works for every line graph question.
Paraphrase the question in your own words. State what the graph shows, including the subject, measurement, location (if given) and time period.
Example: "The line graph illustrates the amount of electricity generated from four renewable sources in the United Kingdom between 1990 and 2020."
This is the most important paragraph for your score. Summarise the main trends without any numbers. What are the biggest changes? Which lines go up and which go down? What is the overall picture?
Example: "Overall, wind and solar power experienced substantial growth over the period, while hydroelectric power remained relatively stable. By 2020, wind had become the dominant source of renewable electricity."
Describe the first group of data in detail. Include specific numbers, starting points, ending points, and notable changes. Use trend vocabulary and make comparisons.
Tip: Start with the most prominent or interesting trend. Use phrases like "Starting at approximately 5 gigawatts in 1990, wind power rose sharply to reach 25 gigawatts by 2020."
Describe the second group of data. Continue with specific numbers and comparisons. Link back to the first body paragraph where relevant.
Tip: Use comparison language: "In contrast to wind power, hydroelectric generation remained largely unchanged at around 8 gigawatts throughout the entire period."
Essential Vocabulary for Describing Trends
Using a range of vocabulary is critical for your Lexical Resource score. Here are the key words and phrases organised by category.
Verbs for Upward Trends
| Verb | Noun Form | Strength | Example |
|---|---|---|---|
| increase | an increase | Neutral | Sales increased from 200 to 350. |
| rise | a rise | Neutral | There was a steady rise in population. |
| grow | growth | Neutral | The economy grew by 3% annually. |
| climb | a climb | Moderate | Temperatures climbed to 35 degrees. |
| surge | a surge | Strong | Demand surged in the final quarter. |
| soar | — | Very strong | House prices soared to record levels. |
| rocket | — | Very strong | The figure rocketed from 10 to 90. |
Verbs for Downward Trends
| Verb | Noun Form | Strength | Example |
|---|---|---|---|
| decrease | a decrease | Neutral | Exports decreased by 15%. |
| fall | a fall | Neutral | There was a sharp fall in profits. |
| decline | a decline | Neutral | Newspaper readership declined steadily. |
| drop | a drop | Moderate | Attendance dropped to 2,000. |
| dip | a dip | Mild/temporary | Sales dipped briefly before recovering. |
| plunge | a plunge | Very strong | Share prices plunged overnight. |
| plummet | — | Very strong | The rate plummeted to an all-time low. |
Verbs for Stability and Fluctuation
| Expression | Meaning | Example |
|---|---|---|
| remain stable / constant | No change | The figure remained stable at around 40%. |
| level off / plateau | Stop changing after a trend | Growth levelled off in 2015. |
| fluctuate | Go up and down irregularly | Prices fluctuated between $30 and $50. |
| peak (at) | Reach the highest point | Tourism peaked at 5 million visitors in July. |
| reach a low / bottom out | Reach the lowest point | Unemployment bottomed out at 3.5%. |
| recover | Go back up after a fall | The market recovered in the second half of the year. |
Adverbs for Degree of Change
- dramatically
- sharply
- significantly
- substantially
- considerably
- steadily
- gradually
- moderately
- progressively
- slightly
- marginally
- minimally
- fractionally
Sample Answer 1: Electricity Generation
The line graph below shows the amount of electricity produced (in terawatt hours) from four renewable energy sources in a European country between 2000 and 2020. Summarise the information by selecting and reporting the main features, and make comparisons where relevant.
Data described: Wind starts at 5 TWh (2000), rises to 8 (2005), 15 (2010), 28 (2015), 45 (2020). Solar starts at 1 TWh (2000), stays at 2 (2005), rises to 5 (2010), 12 (2015), 30 (2020). Hydroelectric stays between 10 and 12 throughout. Biomass starts at 3 (2000) and rises gently to 10 (2020).
The line graph illustrates the electricity generated from four renewable sources — wind, solar, hydroelectric and biomass — in a European country over a twenty-year period from 2000 to 2020.
Overall, wind and solar power saw the most dramatic growth, with wind becoming the largest renewable source by 2020. In contrast, hydroelectric output remained largely unchanged, while biomass showed only modest gains.
In 2000, wind energy produced just 5 terawatt hours (TWh) of electricity, making it the second-largest source after hydroelectric power at approximately 10 TWh. Over the following two decades, wind generation rose sharply and consistently, climbing to 15 TWh by 2010 before accelerating further to reach 45 TWh in 2020 — a ninefold increase. Solar power followed a similar trajectory, albeit from a lower starting point of just 1 TWh. It grew slowly at first, reaching only 5 TWh by 2010, but then surged to 30 TWh by the end of the period.
By contrast, hydroelectric power fluctuated only marginally between 10 and 12 TWh across the entire period, indicating that capacity remained essentially stable. Biomass generation started at 3 TWh in 2000 and rose gradually to 10 TWh by 2020, overtaking hydroelectric power in the final years to become the third-largest source.
Word count: 192 words
Sample Answer 2: Internet Usage by Age
The graph below shows the percentage of people in three age groups who used the internet daily from 2005 to 2020. Summarise the information by selecting and reporting the main features, and make comparisons where relevant.
Data described: Age 16-24: 40% (2005), 60% (2010), 85% (2015), 95% (2020). Age 25-54: 30% (2005), 50% (2010), 75% (2015), 90% (2020). Age 55+: 5% (2005), 15% (2010), 35% (2015), 60% (2020).
The line graph compares the proportion of daily internet users across three age groups — 16 to 24, 25 to 54, and 55 and over — between 2005 and 2020.
Overall, internet usage increased significantly for all three demographics over the period. The youngest group consistently had the highest rates, although the gap between groups narrowed substantially by 2020.
In 2005, 40% of 16-to-24-year-olds used the internet every day, compared with 30% of those aged 25 to 54 and just 5% of people over 55. The youngest cohort saw a steady rise, reaching 60% in 2010, 85% in 2015, and peaking at approximately 95% by the end of the period. Similarly, the 25-to-54 age bracket followed an upward trend, climbing from 30% to 90% over the same timeframe.
The most striking change, however, was among the over-55 group. Starting from a very low base of 5% in 2005, daily usage among older adults increased twelvefold to reach 60% in 2020. Despite this rapid growth, the 55-plus demographic still recorded the lowest rate of daily internet use at the end of the period.
Word count: 178 words
Sample Answer 3: CO2 Emissions
The line graph below shows carbon dioxide emissions (in million tonnes) from transport, industry and residential sectors in a country from 1990 to 2020. Summarise the information by selecting and reporting the main features, and make comparisons where relevant.
Data described: Transport: 80 (1990), 100 (2000), 120 (2010), 110 (2020). Industry: 150 (1990), 130 (2000), 90 (2010), 60 (2020). Residential: 50 (1990), 55 (2000), 50 (2010), 40 (2020).
The line graph depicts carbon dioxide emissions from three sectors — transport, industry and residential — in a country over a thirty-year period starting in 1990.
Overall, industrial emissions declined considerably throughout the period, while transport emissions rose before falling slightly after 2010. Residential emissions showed relatively little change. Notably, by 2020, transport had replaced industry as the largest source of CO2.
Industry was by far the biggest emitter in 1990, producing 150 million tonnes of CO2. However, this figure fell steadily over the following three decades, dropping to 130 million tonnes in 2000, then declining more sharply to 90 million in 2010 and finally reaching 60 million by 2020 — a reduction of 60%. Meanwhile, transport emissions moved in the opposite direction during the first two decades, rising from 80 million tonnes in 1990 to a peak of 120 million in 2010, before dipping slightly to 110 million in 2020.
Residential CO2 output remained the lowest of the three sectors throughout. It hovered around 50 million tonnes from 1990 to 2010, fluctuating only marginally, before falling modestly to 40 million tonnes by the end of the period.
Word count: 183 words
Common Mistakes to Avoid
No Overview
Jumping straight into details without summarising the main trends first. The overview is worth more marks than any body paragraph.
Describing Every Data Point
Trying to mention every number on the graph. Select the most significant data points — starting values, ending values, peaks, troughs, and crossover points.
Giving Opinions or Reasons
Writing "This is because the government invested in renewable energy." You must only describe what the data shows, never explain why.
Repetitive Vocabulary
Using "increased" and "decreased" for every sentence. Vary your language using the vocabulary tables above to score well on Lexical Resource.
Copying the Question
Lifting the exact wording from the question for your introduction. You must paraphrase — change the vocabulary and sentence structure.
Under 150 Words
Writing fewer than 150 words results in a penalty on Task Achievement. Aim for 170-190 words to be safe without spending too long.