Lesson 3 of 125 min read
Prefixes, Suffixes & Meaning
Word parts can reduce the number of possibilities. They do not replace the sentence or a dictionary check. Learn to use them as evidence rather than certainty.
Understand the pattern
A prefix comes before a base and often changes meaning: reread means read again; inaccurate means not accurate. A suffix follows a base and may change the word class: develop becomes development. These patterns help you recognise unfamiliar vocabulary, especially when a passage contains several members of one family.
Do not attach a familiar prefix to any word you like. English uses different negative forms: unable, inaccurate, impossible and irregular. These are established words to learn, not freely interchangeable choices. Also be careful with apparent word parts. Invaluable normally means extremely useful or valuable, not without value.
Treat your first interpretation as a hypothesis. Identify the base, propose a meaning, then test it against the surrounding sentence. If The evidence was insufficient explains why a decision was delayed, not enough fits. If your interpretation makes the passage contradictory, reconsider the word or the sentence relationship.
Language in context
| Word or pattern | Meaning or use | Example |
|---|---|---|
| re-: reconsider | Think about something again | The committee will reconsider the proposal. |
| mis-: misunderstand | Understand incorrectly | I misunderstood the meeting time. |
| -ment: development | Often forms a noun | The development of the service took a year. |
| -able: reusable | Able to be used again | The shop sells reusable containers. |
Worked example
Reason through the choice
The instructions were ambiguous, so several users misinterpreted them. What does misinterpreted suggest?
Answer: Interpreted incorrectly.
The prefix mis- points to an error, and ambiguous instructions make that interpretation plausible. It does not tell us exactly which wrong interpretation each user made. Do not add a detail that the sentence does not provide.
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 with an established word: The figures are not accurate; they are ___.
- The packaging is biodegradable. What should you do if the word parts only give you a partial meaning?
- Rewrite We need to assess the plan again using re-.
Check answers and explanations
1. Inaccurate. The negative form is inaccurate, not unaccurate. Learn the complete word.
2. Use the surrounding explanation and check a dictionary afterwards. A partial clue is useful, but is not enough to justify a precise definition you cannot support.
3. We need to reassess the plan. Reassess is an established verb meaning assess again; the rest of the grammar stays the same.
Use it in your PTE preparation
PTE Academic
Word parts can help with academic families such as interpret, interpretation and misinterpretation. Use them to follow an argument, then verify the precise sense before paraphrasing the author's claim.
PTE Core
Watch prefixes in practical messages: reschedule changes a planned time, unavailable says something cannot currently be used, and misunderstanding names an error in understanding. Small differences may change what action you need to take.
Recall and transfer
Write a positive and negative sentence about the same service using available and unavailable. Then explain the difference between reuse and replace. If your explanation relies only on guessing from letters, add an example to your study record.