Lesson 10 of 125 min read
Data, Comparisons & Change
Clear descriptions of data depend on small words: from, to, by, at and of. Use them accurately before adding more elaborate trend vocabulary.
Understand the pattern
Use from for the starting value, to for the endpoint and by for the amount of change. Attendance rose from 40 to 50 means an increase of 10. Rose by 50 would describe a different change. State the unit where needed: people, dollars, minutes or a percentage.
Percent and percentage points are different measurements. A share increasing from 20% to 30% rises by 10 percentage points. Relative to its original value, that is a 50% increase. If the task does not require a calculation, stating both percentages clearly is often the safest description.
Choose trend verbs to fit the evidence. Remain stable describes little or no change; fluctuate describes movement up and down; peak means reach the highest point in the relevant series. Two endpoints alone do not establish that a value fluctuated in between. Do not invent the path between observations.
Language in context
| Word or pattern | Meaning or use | Example |
|---|---|---|
| rise from X to Y | Identify the start and end | Attendance rose from 40 to 50 people. |
| an increase of X | State the absolute change | There was an increase of ten people. |
| account for | Make up a share of a total | Online orders account for a quarter of sales. |
| remain stable / fluctuate | Stay similar / move up and down | Costs remained stable while demand fluctuated. |
Worked example
Reason through the choice
A proportion moves from 25% to 30%. Describe the change without confusing its two possible measurements.
Answer: It increased by five percentage points, from 25% to 30%.
Subtracting the percentages gives five percentage points. The relative increase is 5 divided by 25, or 20%. Saying it increased by five percent would not accurately describe that relative change.
Try it yourself
Write your answers before opening the key. For open responses, the suggested answer is one possible version; keep the meaning and check the target pattern.
- Complete: Revenue fell ___ 80 ___ 60, a fall ___ 20.
- A series is 10, 14, 11, 16. Is remained stable or fluctuated the better description?
- A share rises from 40% to 50%. Give the percentage-point change.
Check answers and explanations
1. From; to; of. The first two prepositions give endpoints; of introduces the amount after the noun fall.
2. Fluctuated. The values move both up and down. The final value is also higher than the first.
3. Ten percentage points. The relative percentage increase would be 25%, so the two labels must not be mixed.
Use it in your PTE preparation
PTE Academic
In chart-based practice, name the subject, the main comparison and one supporting figure. Keep units and time periods consistent. A chart can show a relationship without establishing the cause of the pattern.
PTE Core
When explaining a price or schedule change, use from and to so the recipient knows both the old and new values. If you mention a difference, check the arithmetic and whether it is an amount, percentage or duration.
Recall and transfer
Invent three values with a clear unit and describe them using a verb and then a noun: increased by; an increase of. Check the arithmetic. Finally, describe one limitation in what your small dataset can tell you.