Punctuation Mistakes That Cost Marks in IELTS Writing
Sanjay from Ranchi joined every idea with a comma. His trainer counted nine comma splices in one essay.
Punctuation is assessed within Grammatical Range and Accuracy, so comma splices, missing commas after opening clauses and apostrophe slips can hold back an otherwise good essay. A few clear rules fix each one.
How Punctuation Affects Your Band Score
The IELTS key assessment criteria list the accurate and appropriate use of punctuation under Grammatical Range and Accuracy. IDP IELTS also calls punctuation an important criterion that examiners mark against.
The public band descriptors say punctuation is often faulty at Band 4 and may be faulty at Band 5. At Band 6, errors in grammar and punctuation occur but rarely impede communication, and at Band 7 grammar and punctuation are generally well controlled.
The IELTS examiner video gives a clear example: it needs to be clear to the reader where a sentence begins and where it ends, or communication can suffer.
Eight Punctuation Mistakes and How to Fix Them
| ❌ Error | ✅ Correction | Rule in brief |
|---|---|---|
| Traffic grew, councils built roads. | Traffic grew. Councils built roads. | A comma alone should not join two full sentences. |
| Although taxes rose sales climbed. | Although taxes rose, sales climbed. | Put a comma after an opening ‘although’ clause. |
| The company expanded it’s operations. | The company expanded its operations. | ‘Its’ shows possession; ‘it’s’ means ‘it is’. |
| Many student’s study overseas. | Many students study overseas. | A simple plural takes no apostrophe. |
| The report was clear , accurate and useful. | The report was clear, accurate and useful. | No space before a comma; one space after. |
| Growth slowed. however, profits held. | Growth slowed. However, profits held. | A new sentence starts with a capital letter. |
| Smog increased; but councils acted. | Smog increased, but councils acted. | Use a comma before ‘but’, or a semicolon without it. |
| Smog is rising schools have closed. | Smog is rising, so schools have closed. | Two sentences need a full stop, semicolon or conjunction. |
For more detail, see our lessons on eight essential comma rules and possessive nouns and apostrophes.
Fixing Comma Splices and Boundary Errors
A comma splice joins two complete sentences with just a comma. In formal English, a comma on its own should not do that job.
Incorrect: “Cities expanded rapidly, public transport did not keep up.”
Correct: “Cities expanded rapidly, but public transport did not keep up.”
A full stop or a semicolon would also work; the conjunction adds the contrast.
For closely linked ideas, a semicolon is another option. Learn how it works in our lesson on semicolons and colons.
Typing Habits on Computer-Delivered Tests
If you type your answers, watch for spaces before commas and full stops, and for a missing capital letter after a full stop. They matter because it should be clear to the reader where each sentence begins and ends.
IDP IELTS also says you can use either British or American English. Some punctuation choices, such as the serial comma before “and”, are a matter of style, so choose one habit and apply it consistently.
Tip
In your final check, look at the first and last word of each sentence: a capital letter to start and a full stop to end.
Try It
Practice task (written for this post)
The paragraph below contains five punctuation errors. Find and correct them.
Many graduates struggle to find employment, competition for entry-level roles has intensified. Although university degrees remain popular student’s tend to lack practical skills. furthermore, multinational firm’s have reduced their graduate recruitment programmes.
Show sample answer
Many graduates struggle to find employment. Competition for entry-level roles has intensified. Although university degrees remain popular, students tend to lack practical skills. Furthermore, multinational firms have reduced their graduate recruitment programmes.
Corrections:
- Comma splice: the comma after “employment” became a full stop, and “Competition” got a capital letter.
- Missing comma: one was added after the opening clause ending in “popular”.
- Plural apostrophe: “student’s” became “students”.
- Missing capital: “furthermore” became “Furthermore” after the full stop.
- Plural apostrophe: “firm’s” became “firms”.
Key Takeaways
- Punctuation is assessed within Grammatical Range and Accuracy.
- Band 7 needs grammar and punctuation that are generally well controlled.
- A comma alone should not join two full sentences.
- On screen, check for spaces before commas and capitals after full stops.
The bottom line: Sanjay did not need new grammar; he needed to decide, at the end of each idea, whether a full stop, a comma or a conjunction belonged there.