7 WritingRead the time period, unit and groups before describing a line graph. Use the overview for major trends and relationships, then support them with selected figures. Avoid giving every year its own sentence.
Separate the overview from detail
If two series rise, describe that shared trend and identify the stronger increase. In the detail paragraphs, choose starting and ending values and any important turning point. Not every data point needs equal attention.
Match the number to its unit
A change from 10% to 20% is an increase of ten percentage points, not ten per cent. A percentage chart does not by itself establish a change in total population. Do not invent policy or demographic explanations when the chart supplies none.
Practice question
A practice line graph shows the percentage of commuters cycling in Northbridge and Southbridge. In 2015, 2020 and 2025, the figures were 10%, 15% and 25% for Northbridge, and 20%, 22% and 24% for Southbridge. Summarise the information and make comparisons where relevant.
Illustrative paragraph
Overall, cycling became more common in both towns, but the increase was considerably larger in Northbridge. Its figure rose from 10% in 2015 to 25% in 2025, while Southbridge recorded a smaller rise from 20% to 24%. Northbridge therefore moved from the lower starting point to a slightly higher final proportion.
Check your paragraph
Cover the illustrative paragraph and explain the purpose of each sentence in your own words. Then change one detail and rewrite it. Check that the claim still follows from the evidence. Do not just replace synonyms; if the meaning changes, revise the reason as well.
Continue practising
Read the practice workflow before planning comparisons.