Writing · Unit 3: Core strategies
W21: Task 1 line graph, step by step
Target band 6.5 to 7
Line graphs are the most common Task 1 type. They show how something changes over time. The skill is to describe the big movements, not every small wiggle, and to compare the lines with each other. Here's a step-by-step method and a full model answer.
Why this matters
If you master line graphs, you also learn the trend language you need for bar charts and tables with time periods. It's the foundation of Task 1.
The 4-step method
- Read the graph (2 minutes). What's measured? What units? What period? How many lines?
- Find the story (1 minute). Which line ends highest? Which changed most? Do any lines cross?
- Plan your paragraphs. Group the lines logically, for example rising lines in one paragraph and falling lines in the other.
- Write: introduction, overview, body 1, body 2.
The data
The graph shows electricity generated from three sources in Country X, 2000 to 2025, in terawatt hours (TWh).
| Year | Coal | Gas | Solar |
|---|---|---|---|
| 2000 | 60 | 30 | 0 |
| 2005 | 70 | 35 | 2 |
| 2010 | 75 | 45 | 5 |
| 2015 | 65 | 55 | 15 |
| 2020 | 50 | 60 | 30 |
| 2025 | 35 | 58 | 50 |
(For your video, draw this as a line graph with three lines.)
Finding the story
- Coal rose, peaked in 2010, then fell steadily.
- Gas grew, then levelled off.
- Solar started at zero and grew dramatically, overtaking coal by 2025.
Model answer (about 180 words)
The line graph illustrates how much electricity was produced from coal, gas and solar power in Country X between 2000 and 2025.
Overall, coal declined after an early peak, while gas and especially solar power grew significantly. By the end of the period, solar had overtaken coal, and gas had become the largest source.
Coal was the main source of electricity at the start of the period, rising from 60 TWh in 2000 to a peak of 75 TWh in 2010. After this, however, it fell steadily, dropping to just 35 TWh by 2025, less than half its peak level.
In contrast, gas generation increased consistently for most of the period, from 30 TWh to 60 TWh in 2020, before levelling off at around 58 TWh. The most dramatic change was in solar power. Starting from zero in 2000, it grew slowly at first, reaching only 5 TWh in 2010, but then rose rapidly to 50 TWh in 2025, overtaking coal in the final years.
Why this answer works
- Clear overview in paragraph 2, with no detailed numbers.
- Grouping: coal (falling) in one paragraph; gas and solar (rising) in the other.
- Selected numbers: start, peak, end, and the crossover.
- Varied trend language: rising to a peak, fell steadily, levelling off, rose rapidly, overtaking.
Useful line graph phrases
| Movement | Verbs | Adverbs |
|---|---|---|
| Up | rose, increased, grew, climbed | sharply, rapidly, steadily, gradually |
| Down | fell, dropped, declined, decreased | dramatically, slightly, steadily |
| Top | peaked at, reached a high of | |
| Bottom | hit a low of, bottomed out at | |
| No change | remained stable, levelled off, stayed at | |
| Up and down | fluctuated |
Try it yourself
Write one sentence about gas using levelled off.
Sample answer: "Gas output climbed steadily to 60 TWh in 2020, after which it levelled off."
Honest note
This model is one good way, not the only way. Another student could group differently and still score well. What matters is a clear overview, logical grouping and accurate data.
Your task today
Write your own answer to this graph in 20 minutes, without looking at the model. Then compare.