This complete guide explains how to describe line graphs and other charts showing changes over time in IELTS Writing Task 1 Academic.
You will learn the vocabulary needed to describe trends, increases, decreases and fluctuations, how to identify key features, how to write a clear overview and how to structure a Band 7+ answer.
The guide also includes practice exercises and model answers based on real IELTS questions.
What is a line graph in IELTS Writing Task 1?
📈 IELTS Writing Task 1 line graphs show how data changes over months, years or other periods of time. Bar charts, tables and mixed charts can also show changes over time.
When you answer this type of question, you should focus on the main trends and key features – explain what went up, what went down and any important patterns in the data.
You do not need to describe every number.
📉 Some people call this a ‘dynamic’ graph or chart (compare with a ‘static’ chart, where there are no changes – see Task 1 Bar Charts: How to compare and contrast data).
In this lesson, you’ll review
- Key features
- Verbs of change
- Adverbs of change
- Nouns of change
- Prepositions
- Making comparisons
- Adding data
- Choosing tenses
- Paraphrasing the introduction
- Writing the overview
- Models and Practice
- What next?
We will be using the example below from a Cambridge Past Paper.
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How to identify the KEY features in a line graph
Task Achievement Band Descriptors
✅ Band 7: ‘Key features which are selected are covered and clearly highlighted‘
🙁 Band 5: ‘The recounting of detail is mainly mechanical’
The first thing you need to do is identify 3 KEY FEATURES and general trends.
You don’t have much time to do this, so ask yourself:
- What went up? 📈
- What went down? 📉
- What stayed the same or did something different? 👩🏼🎤 (What stood out?)
When you do this, you’ll start to see patterns.
Do this now with the dynamic chart below.
- They ALL dropped in the first 5 months
- They ALL went back up in June
- The ALL stayed the same in the summer months (July – September)
- They ALL increased towards the end of the year (less noticeable for copper).
NOTE
There may be other key features related to comparisons between the 3 metals e.g.
- Nickel saw the biggest drop in value (see point #6).
But in this lesson we will focus on the language of change.
IELTS line graph vocabulary
There are about 20 verbs that describe change.
Memorise them, and learn their past tense forms.
Vocabulary for INCREASES 📈
| Verb | Past tense form |
|---|---|
| go up | went up (to/by) |
| grow | grew (to/by) |
| rise | rose (to/by) |
| climb | climbed (to/by) |
| rocket | rocketed (to/by) |
| soar | soared (to/by) |
| shoot up | shot up (to/by) |
| recover | recovered |
| peak | peaked (at) |
Vocabulary for DECREASES 📉
| Verb | Past tense form |
|---|---|
| go down | went down (to/by) |
| fall | fell (to/by) |
| drop | dropped (to/by) |
| decline | declined (to/by) |
| sink | sank (to/by) |
| slump | slumped (to/by) |
| plummet | plummeted (to/by) |
| collapse | collapsed |
| dip | dipped |
Vocabulary for high points and low points
it reached a peak (at/of) ⛰️
it hit its lowest point (at/of)
it hit its highest level
Vocabulary for fluctuations
- fluctuated (went up and down)
Vocabulary for staying the same
- levelled out/off (at)
- remained steady (at)
- evened out (at)
- stayed the same (at)
- stabilised (at)
Other useful verbs for describing changes
- doubled (became 2 times bigger)
- tripled (became 3 times bigger)
- halved (became half as much)
- increased/decreased by a third, quarter or fifth
- overtook (became higher than another figure)
EXAMPLE
Sales of coffee overtook sales of tea in 2015.
Common mistakes with line graphs
Describing every data point
❌ In 2000 it was 10%, in 2001 it was 11%, in 2002 it was 12%…
✅ Focus on the main trends and key features.
Examiners want a summary, not a list of numbers.
Writing opinions
❌ People probably preferred cars because they were more comfortable.
✅ Car ownership increased significantly.
Forgetting the overview
✅ Include a clear overview of the main trends.
Using dramatic vocabulary for small changes
❌ Sales rocketed from 50 to 52.
✅ Sales rose slightly from 50 to 52.
Strong verbs should only be used for large changes.
Common grammar mistakes with line graphs
Using the wrong tense
❌ Between 2000 and 2010, sales increase steadily.
✅ Between 2000 and 2010, sales increased steadily.
1. Using fell down
❌ The number of visitors fell down to 500.
✅ The number of visitors fell to 500.
✅ The number of visitors went down to 500.
2. Using grew up
❌ Sales grew up to 200 units.
✅ Sales grew to 200 units.
✅ Sales increased to 200 units.
‘Grow up’ means to become an adult.
‘peaked’
‘GREW’ and ‘FELL’
How to use ADVERBS of change
Adverbs can help you describe a change more accurately. They tell the reader how fast a change happened or how big the change was.
1. Adverbs of speed
Use these adverbs to describe how quickly something changed.
- slowly
- steadily
- gradually
- suddenly
- quickly
- sharply
- rapidly
2. Adverbs of size
Use these adverbs to describe the size of the change.
- slightly
- moderately
- significantly
- considerably
- substantially
- noticeably
- dramatically
Examples
✅ Sales increased steadily.
✅ Sales increased gradually.
✅ Sales increased dramatically.
✅ Sales increased significantly.
You can also use a noun phrase instead:
✅ Sales increased at a steady pace.
✅ Sales increased at a gradual rate.
Tip
Choose an adverb that matches the data. A small increase should be described as slight, while a large increase can be described as significant, substantial or dramatic.
❌ Sales rose dramatically from 50 to 52.
✅ Sales rose slightly from 50 to 52.
How to use NOUNS of change
Grammar Band Descriptor
✅ Band 7: A variety of complex structures is used with some flexibility and accuracy.
😟 Band 5: The range of structures is limited and rather repetitive.
If you only use verbs and adverbs, your writing can become repetitive. A good way to add variety to your language is to use nouns of change.
Compare these two sentences:
- Verb + adverb: Sales increased slowly.
- Adjective + noun: There was a slow increase in sales.
Both sentences describe the same trend, but using a mix of structures will make your writing more flexible and help you demonstrate a wider range of vocabulary.
Common nouns of change
- an increase
- a rise
- growth (usually uncountable, so no article)
- a decrease
- a drop
- a fall
- a decline
- a dip
- a reduction
Adjectives of speed
Use these adjectives to describe how quickly the change happened.
- slow
- steady
- sudden
- sharp
- rapid
- dramatic
Adjectives of size
Use these adjectives to describe how large the change was.
- slight
- moderate
- modest
- significant
- considerable
- substantial
- noticeable
- steep
Examples
✅ There was a significant drop in the price of nickel.
✅ There was a steady increase in sales.
✅ The price of nickel saw significant growth.
✅ The company experienced a substantial rise in profits.
✅ Car sales underwent a sharp decline.
Tip
When using a noun of change, remember this common pattern:
There was + adjective + noun + in
Examples:
- There was a sharp increase in sales.
- There was a slight decline in unemployment.
- There was a dramatic fall in the number of visitors.
This is one of the most useful structures for IELTS Writing Task 1 and can help you avoid repeating verbs such as increase, rise and fall.
How to use prepositions
Many IELTS candidates confuse the prepositions to, at and by when describing changes. Learning the difference will help you avoid common grammar mistakes.
What’s the difference?
- Sales fell to 10%.
- Sales remained steady at 10%.
- Sales fell by 10%.
- ‘to’ shows something MOVED (e.g. fell from 20% to 10%)
- ‘at’ shows something stayed at the same place
- ‘by’ describes the amount of change (e.g. from 90% to 80% = fell by 10%
- Sales fell from 20% to 10%.
- The number of visitors increased to 5,000.
‘at’ shows a fixed level.
- Sales remained steady at 10%.
- Unemployment stood at 8%.
‘by’ shows the amount of change.
- Sales fell by 10%.
- The figure increased by 500 units.
Prepositions and time expressions
When describing a graph, you often need to say when something happened.
Time periods
Use these expressions to describe a period of time:
- from January to June
- between January and June
- during this period
- over a decade
- over a 10-year period
Years and months
Use in with years and months:
- in 2014
- in May
- in the final year
Noun phrases
Use in after nouns of change:
- an increase in sales
- a decline in population
- a drop in demand
- a rise in prices
The beginning and end of a period
- at the start of the period
- at the beginning of the period
- at the end of the period
Examples:
- Car ownership was highest at the start of the period.
- The figure reached its peak at the end of the period.
Making comparisons
When describing a line graph, most students read the data from left to right and explain how it changes over time. This is important, but it is not enough.
You should also look at the graph from top to bottom ↕️ and compare the different categories with each other. This will help you identify important features and write a stronger overview.
For example
- Nickel showed the most significant price fluctuations.
- The changes for copper and zinc were less dramatic.
- Nickel started the period with the highest percentage change but ended with the lowest.
- Copper remained more stable than the other metals.
- Zinc experienced a greater increase than copper.
Useful language for comparisons
You can use the following expressions when two categories behave in a similar or different way:
- … followed a similar trend.
- … followed a different trend.
- … followed the same pattern.
- … followed the opposite trend.
- The same was true for …
- The opposite was true for …
- … but to a lesser extent.
- … but to a greater extent.
Examples
✅ Copper followed a similar trend to zinc.
✅ Prices increased in all three metals, but to a lesser extent for copper.
✅ Nickel rose sharply, while the opposite was true for zinc.
✅ Copper and zinc followed the same pattern, although the increase was more noticeable for zinc.
Tip
Good IELTS Task 1 answers do not simply describe each line separately. They also compare the different categories and highlight important similarities and differences.
For more help, see my guide on how to compare and contrast in IELTS Writing Task 1.
Adding data to your description
Now that you have identified the key features and learned the language to describe them, you need to support your ideas with data from the graph.
However, be careful not to include too many figures. In IELTS Writing Task 1, it is better to select a few important numbers that support the main trends rather than describe every data point.
A useful technique is to describe the trend first and then add the relevant data.
Examples
- Nickel prices fell considerably, dropping from 6% to -3% during the first six months of the year.
- Copper prices remained steady, at around 1% during the summer months.
- The changes for the other two minerals were less noticeable, with zinc peaking at 3%.
Use approximations
The numbers in a graph do not always need to be exact. In fact, approximations often make your writing easier to read and sound more natural.
Useful expressions include:
- about
- around
- approximately
- nearly
- just under
- just over
Examples
✅ Sales rose to around 500 units.
✅ The figure peaked at approximately 15%.
✅ Unemployment fell to just under 6%.
✅ Car ownership reached nearly 80%.
Tip
Try to include data naturally in your sentences. Start with the trend, then add the figures to support it.
❌ In 2000, sales were 100. In 2005, they were 150. In 2010, they were 200.
✅ Sales increased steadily, rising from 100 in 2000 to 200 in 2010.
This approach helps you focus on the main trends and key features, which is exactly what the examiner is looking for.
See also: How to use -ing clauses to add data (Members Resource Library)
Choosing the correct tense
Most graphs that show changes over time use data from the past. In these cases, you should use the Past Simple tense.
Examples
✅ Sales rose steadily between 2010 and 2015.
✅ The figure fell sharply in 2014.
✅ Nickel prices remained stable during the final quarter.
Using the Past Perfect
The Past Perfect can be used when you want to describe a change that happened before another point in the past.
For example:
✅ By March, the percentage change for nickel had dropped to 1%.
✅ By the end of June, sales had increased to almost 500 units.
However, don’t force the Past Perfect into every answer. For most IELTS Task 1 questions, the Past Simple is enough.
What if the graph shows future data?
Some IELTS Task 1 questions include predictions or projections. In these cases, you may need to use future forms.
✅ Sales are expected to increase over the next five years.
✅ The figure is predicted to reach 80% by 2030.
Tip
Before you start writing, check the dates on the graph. The dates will tell you which tense to use.
- Past dates → Past Simple
- Earlier past event → Past Perfect
- Future predictions → Future forms
See also:
Paraphrasing the introduction
No matter what type of graph you are describing, you should begin by paraphrasing the task statement. However, this does not mean changing every word.
Look at this example:
Task statement
The line chart below shows the average monthly change in the prices of copper, nickel and zinc in 2014.
Paraphrased introduction
The line chart gives information about the monthly percentage change in the prices of copper, nickel and zinc in 2014.
What do you notice?
- You do not need to change every word.
- Simple changes are enough. For example: shows → gives information about
- You can name the categories in the graph: copper, nickel and zinc
- Some time expressions can be changed: during 2014 → in 2014
Changing time periods
When the task includes a fixed period such as:
from 2010 to 2020
you can write:
- between 2010 and 2020
- over a 10-year period
- over a decade
More examples
Original
The graph shows changes in car ownership from 2000 to 2010.
Paraphrased
The graph gives information about changes in car ownership between 2000 and 2010.
Original
The line chart shows the number of visitors during a 10-year period.
Paraphrased
The line chart illustrates the number of visitors over a decade.
Keep it simple
Many websites and social media accounts recommend long lists of synonyms for words such as show. This often leads to unnatural or inaccurate language.
Remember:
✅ Clear and accurate language is better than complicated vocabulary.
✅ You only need to make a few changes to the original sentence.
Common mistakes
Avoid phrases such as:
❌ the given graph
❌ the provided chart
❌ the chart below
❌ the supplied line graph
These expressions are unnecessary. Simply write:
✅ The graph shows…
✅ The line chart gives information about…
✅ The chart illustrates…
That’s all you need for a clear introduction.
Writing the overview
Write the overview immediately after your introduction.
The overview is the most important part of your answer because it summarises the main trends in the graph. Without a clear overview, it is difficult to achieve a high score for Task Achievement.
A good overview should:
- describe one or two general trends
- highlight any important features or contrasts
- avoid specific details where possible
- usually be one or two sentences long
Example
✅ Overall, there was a decline in the prices of all three metals, most noticeably for nickel.
Notice that this overview focuses on the general trend. It does not include unnecessary figures or detailed information.
Highlighting contrasts
A strong overview often identifies the most important contrast in the data.
✅ Overall, although nickel started the year with the highest percentage change of the three metals, it ended with the lowest.
This is an effective overview because it highlights a key feature and uses a complex sentence naturally.
What should you look for?
Before writing your overview, ask yourself:
- What increased?
- What decreased?
- What stayed the same?
- Which category had the highest figure?
- Which category had the lowest figure?
- Were there any unusual patterns?
Your answers will usually provide the content for the overview.
Common mistakes
❌ Writing an overview with lots of data.
❌ Describing every line separately.
❌ Repeating information from the body paragraphs.
❌ Forgetting the overview completely.
Tip
Imagine that you only have one sentence to describe the graph to someone who cannot see it. What is the most important thing they need to know?
The answer to that question is usually your overview.
Models and practice
Now that you know how to identify key features, describe trends, make comparisons and add data, the next step is practice.
If you follow the techniques in this guide and the tips in my IELTS Writing Task 1 guide, you will be able to describe any graph that shows changes over time.
How to practise effectively
- Practise with a variety of line graphs, bar charts and tables.
- Focus on identifying the key features before you start writing.
- Gradually reduce your writing time until you can complete the task in 20 minutes.
- Review your work and check your use of vocabulary, grammar and data.
Read model answers
One of the best ways to improve your writing is to read high-quality examples. Pay attention to how good writers:
- write clear overviews
- describe trends accurately
- make comparisons
- include data naturally
- use a range of vocabulary
You can also read real examples of data analysis to become more familiar with the language used to describe graphs and trends. I regularly post and analyse examples in my Daily Tips.
Final tip
Don’t try to memorise complete answers. Instead, learn the patterns and vocabulary in this guide, then practise applying them to different questions. This will help you write a clear, flexible response on test day, no matter what graph you are given.
Possible Model Answer
I’ve organised my response according to the time periods.
You could also organise it according to the different metals, but this might lead to a more simplistic and repetitive response (the Band 6 example in the Cambridge Test Book was organised like this).
187 words
The line chart gives information about the change in monthly prices for copper, nickel and zinc in 2014. Overall, there was a decline in the prices of all three metals, most noticeably for nickel.
At the start of the period, the percentage change for nickel (6%) was much higher than copper and zinc (2% and 1% respectively). However, by March, the change for nickel had dropped to 1% and it saw a low of -3% in June. The changes for the other two minerals were less marked, with zinc peaking at 3% in February before a declining trend over the remainder of the first half of the year. Similarly, copper prices fell but were slightly lower at around 1% to -1%.
In the second half of the year, the prices for all three metals were stagnant from July to September. Nickel prices then dipped before a steep rise to finish the year at 1%. The price of copper also fell before a rise in December. Zinc followed a similar trend, with a 2% increase in December, ending the period with the highest change of all mineral prices.
Read the model answer above, and test yourself here (if you can’t see the quiz on your phone, please try your laptop/desktop).
Ready to take your Task 1 writing to the next level?
This guide has shown you how to:
- identify key features
- write effective overviews
- describe trends and changes accurately
- use a wider range of vocabulary and grammar
- support your ideas with data
However, knowing the techniques is only the first step. To improve your score, you need a clear study plan and regular practice.
Still struggling with Writing Task 1?
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