Direct answer: To describe a complex line graph, paraphrase the title, write an overview of the main trends and any crossovers, then group the lines by pattern into two body paragraphs. Support each trend with selected, accurate figures and varied trend language. Write at least 150 words in about 20 minutes.
A line graph with four or five lines is hard because you cannot describe everything. The skill the exam tests is selection: choosing the key features, grouping them, and reporting them accurately. This guide gives you a repeatable method, a worked example, a language bank, common errors and a practice task. For the wider exam plan, see our hub guide, IELTS Preparation (Academic & General Training).
What the examiner is looking for
Line graphs appear in IELTS Academic Writing Task 1 only. General Training Task 1 is a letter. You must write at least 150 words, and the recommended time is about 20 minutes. Task 1 carries one-third of the Writing marks.
Your response is assessed on four equally weighted criteria:
- Task Achievement: accurate data, a clear overview, relevant key features.
- Coherence and Cohesion: logical paragraphs and linking.
- Lexical Resource: range and precision of vocabulary.
- Grammatical Range and Accuracy: varied, correct structures.
The official band descriptors reward a clear overview of the main trends from the higher bands upward. They also expect key features to be highlighted and supported with data. A response that lists numbers without an overview cannot score well on Task Achievement.
The four-step method
Step 1: Read the graph (2 minutes)
Check four things before you write:
- Title and units: percentages, thousands, millions or tonnes?
- Time period: past, present or future? This decides your tenses.
- Overall direction of each line: rising, falling, fluctuating or stable.
- Special points: the highest and lowest values, crossovers and turning points.
Mark these on the question paper. Ignore everything else.
Step 2: Paraphrase the introduction (1 sentence)
Change the wording of the title without changing the meaning. For example, “The graph shows the percentage of households using three types of internet connection” becomes “The line graph compares how common three kinds of internet access were among households between 2000 and 2020.”
Step 3: Write the overview (2 sentences)
State the main trends and the most striking comparison, with no detailed numbers. Never leave the overview until a “conclusion”. Place it directly after the introduction, or as the first body paragraph. Both positions are acceptable.
Step 4: Group the lines in two body paragraphs
Do not describe one line at a time in the order they appear in the legend. Group lines by pattern (those that fall together, those that rise) or by time (before and after a crossover). Open each paragraph with the grouping idea, then add figures, a starting value, a turning point and an end value.
Worked example
This is a fictional chart I wrote for practice. The figures are invented and not real statistics.
Percentage of households using each connection type (fictional data)
| Year | Dial-up | Broadband | Mobile data |
|—|—|—|—|
| 2000 | 40 | 5 | 0 |
| 2005 | 30 | 35 | 3 |
| 2010 | 12 | 60 | 20 |
| 2015 | 5 | 70 | 50 |
| 2020 | 2 | 65 | 80 |
Model answer (about 190 words):
The line graph compares the proportion of households using dial-up, broadband and mobile data connections between 2000 and 2020.
Overall, dial-up use declined steadily to a negligible level, whereas the other two types became far more common. Broadband was the most widely used connection for most of the period, but mobile data overtook it by the end.
Dial-up was the leading connection in 2000, at 40%, but it then fell consistently, dropping to 12% in 2010 and just 2% in 2020. Broadband moved in the opposite direction. Starting at only 5%, it rose sharply and passed dial-up between 2000 and 2005. It peaked at 70% in 2015 before dipping slightly to 65% in 2020.
Mobile data was non-existent in 2000 and remained marginal (3%) in 2005. It then grew rapidly, reaching 20% in 2010 and 50% in 2015. By 2020 it had climbed to 80%, overtaking broadband, which made it the most popular option.
Note the techniques:
- The overview contains no figures.
- Dial-up is described alone because it is the only falling line.
- Broadband and mobile are linked through the crossover.
- Only turning points and key values are quoted.
Language bank for multiple trends
Verbs and nouns
| Meaning | Verbs | Nouns |
|—|—|—|
| Go up | rise, increase, climb, grow | a rise, an increase, growth |
| Go down | fall, decline, decrease, drop | a fall, a decline, a drop |
| Big, fast change | surge, soar, plummet | a surge, a sharp fall |
| Small change | edge up, dip, slip | a slight rise, a minor dip |
| No change | remain stable, stay constant, level off | a plateau |
| Up and down | fluctuate | fluctuations |
| Highest/lowest | peak at, reach a low of, bottom out at | a peak, a low point |
Prepositions and linking
- Increase to 50% gives the new figure. Increase by 10% gives the size of the change. From 20% to 50% gives the start and end.
- Use at for a level: “stood at 30%”. Use between 2005 and 2010 or from 2005 to 2010 for periods.
- Contrast with whereas, while, in contrast and however. Show sequence with then, after that, by 2020 and subsequently.
- Show crossovers with overtook, surpassed, fell below and became the most popular.
Tense and style notes
- Use the past simple for finished periods. Use the future (“is expected to”, “will”) only for projections shown on the graph.
- Write “per cent” (British style) or “percent” (American style). The % symbol is also fine. Either spelling is accepted in IELTS, so be consistent.
- Use the number of with countable items and the proportion/percentage of with percentages. Use fewer with countable nouns.
- Do not explain causes. The graph does not tell you why a trend happened, so giving reasons is speculation.
Common mistakes and corrections
| Mistake | Correction |
|—|—|
| No overview, or an overview only at the end | Put a 2-sentence overview of trends right after the introduction |
| Listing every data point | Select peaks, lows, turning points and crossovers |
| “Broadband increased by 70% in 2015.” | “Broadband increased to 70% in 2015.” (by describes change size) |
| “The percentage of dial-up was decreased.” | “The percentage of dial-up decreased.” (decrease is intransitive here) |
| “Mobile data was risen quickly.” | “Mobile data rose quickly.” (rise has no passive) |
| Describing lines in legend order | Group by pattern or time |
| “Dial-up is going down because people prefer Wi-Fi.” | “Dial-up fell steadily.” (no invented reasons) |
| Present tense for 2000–2020 | Use past tenses |
| Repeating “increased” six times | Vary verbs and nouns, but keep the meaning accurate (do not use soar for a small rise) |
| Missing a crossover | Add a phrase such as “overtook” or “fell below” |
Practice task
Here is a fictional mini-graph of average monthly sales (thousand cups) at a café.
| Year | Coffee | Tea | Hot chocolate |
|—|—|—|—|
| 2010 | 50 | 20 | 15 |
| 2015 | 60 | 30 | 15 |
| 2020 | 40 | 45 | 14 |
A. Write one overview sentence.
B. Write one sentence about the crossover.
C. Correct this sentence: “Tea sales were increased by 45 thousand cups in 2020.”
D. Correct this sentence: “Hot chocolate sales were fluctuated in the whole period.”
Suggested answers
- A. “Overall, tea sales rose steadily and eventually exceeded coffee sales, while hot chocolate remained almost unchanged.” Other wording is fine if it states the trends and has no detailed figures.
- B. “Coffee sales peaked at 60 thousand cups in 2015 before falling to 40 thousand in 2020, when tea overtook it at 45 thousand.”
- C. “Tea sales increased to 45 thousand cups in 2020.” (to gives the new level, and increase is not used in the passive here.) Alternatively: “Tea sales rose by 25 thousand cups between 2010 and 2020.”
- D. “Hot chocolate sales remained stable throughout the period.” Hot chocolate figures barely change (15, 15, 14), so “fluctuated” is also inaccurate, not just ungrammatical.
Get feedback on your own writing
Practice improves your writing only when someone checks it. Paste your draft sentences or full paragraphs into the English Forward Community Forum (Essay & Composition Writing). You will get feedback from the English Forward community and our AI writing coach on your overview, data accuracy and trend language.
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