Line graphs always show changes over time. Here's some advice about how to describe them:
- Try to write 4 paragraphs - introduction, summary of main points, 2 detail paragraphs.
- For your summary paragraph, look at the "big picture" - what changes happened to all of the lines from the beginning to the end of the period shown (i.e. from the first year to the last). Is there a trend that all of the lines follow (e.g. an overall increase)?
- You don't need to give numbers in your summary paragraph. Numbers are specific details. Just mention general things like 'overall change', 'highest' and 'lowest', without giving specific figures.
- Never describe each line separately. The examiner wants to see comparisons.
- If the graph shows years, you won't have time to mention all of them. The key years to describe are the first year and the last year. You should also mention any 'special' years (e.g. a peak or a significant rise/fall).
- Start describing details (paragraph 3) with a comparison of the lines for the first year shown on the graph (e.g. In 1990, the number of...).
- Use the past simple (increased, fell) for past years, and 'will' or 'is expected/predicted to' for future years.
- Don't use the passive (e.g. the number was increased), continuous (e.g. the number was increasing), or perfect tenses (e.g. the number has increased).