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Grammar · Punctuation · B1 · Intermediate

Oxford comma

Last updated 21 July 2026

In short

The Oxford comma (or serial comma) is the optional comma placed before 'and' or 'or' at the end of a list of three or more items: 'coffee, tea, and juice.' Both using it and dropping it are correct in standard English — the only rule that matters is staying consistent throughout the same piece of writing.

What is the Oxford comma?

The Oxford comma is the comma placed directly before the final 'and' or 'or' in a list of three or more items. 'Bread, cheese, and grapes' uses it; 'bread, cheese and grapes' doesn't — both are grammatically correct.

It takes its name from Oxford University Press style guides, which have long recommended it, though it's used (or dropped) across both British and American English depending on the publication.

  • The bag contained a notebook, a pen, and a bottle of water.(Oxford comma before 'and')
  • The bag contained a notebook, a pen and a bottle of water.(no Oxford comma — equally correct)

When does the Oxford comma prevent ambiguity?

In most lists, the comma is a style choice with no effect on meaning. But when a list item could be misread as describing another item, the Oxford comma removes the ambiguity by clearly separating them.

This is the strongest practical argument in favour of always using it: a missing Oxford comma can occasionally turn a simple list into a confusing sentence.

  • I'd like to thank my parents, Marie Curie, and my tutor.(three separate items — clear thanks to three people)
  • I'd like to thank my parents, Marie Curie and my tutor.(without the comma this could misread as 'my parents' being Marie Curie and my tutor)
  • The exhibition featured photos of the mountains, a local farmer, and his dog.(comma keeps the farmer and his dog as separate items)

Do you need the Oxford comma in IELTS writing?

No. IELTS does not require or prefer either style — examiners accept lists with or without the Oxford comma, as both are standard in different varieties of English. What matters for Grammatical Range and Accuracy is that you punctuate lists correctly and consistently, not which style you pick.

Pick one approach for your whole test and stick to it; switching between the two styles within the same piece of writing can look inconsistent, even though neither style is wrong on its own.

  • The report analyses cost, efficiency, and sustainability.(consistent Oxford-comma style)
  • The plan improves transport, reduces emissions and lowers costs.(consistent no-Oxford-comma style)

Does the Oxford comma apply to two-item lists?

No — the Oxford comma only concerns lists of three or more items. A list of exactly two items joined by 'and' or 'or' never takes a comma before the conjunction, regardless of which style you otherwise prefer.

  • She ordered soup and salad.(only two items — no comma before 'and')
  • She ordered soup, and salad.(a comma before 'and' with only two items is always wrong → soup and salad)

Does the same choice apply to a list of clauses?

The same optional-comma choice extends to a list of three short clauses, each with its own verb: you may add a comma before the final 'and', or leave it out, as long as you're consistent within the sentence and the wider text.

  • He booked the flights, packed his bags, and left for the airport.
  • He booked the flights, packed his bags and left for the airport.(also correct — no Oxford comma)

Common mistakes with oxford comma

Real learner errors, corrected and explained — the fastest way to stop repeating them.

We visited Paris, Rome, and, Berlin.

We visited Paris, Rome, and Berlin.

The Oxford comma goes before 'and', not after it — there's only ever one comma at that position.

I ordered tea, and coffee.

I ordered tea and coffee.

The Oxford comma only applies to lists of three or more items; a plain two-item list never takes a comma before 'and'.

The menu offers soup, a sandwich with fries and a drink.

The menu offers soup, a sandwich with fries, and a drink.

Without the Oxford comma before 'and', it's unclear whether 'fries and a drink' are both part of the sandwich item — the comma separates the two final items clearly.

This report is dedicated to my professor, an inspiring mentor and my closest friend.

This report is dedicated to my professor, an inspiring mentor, and my closest friend.

Without the final comma, the sentence could be misread as describing only one person ('my professor, an inspiring mentor') followed by a second, rather than naming three separate people — the Oxford comma removes the ambiguity.

We need volunteers, staff and, managers for the event.

We need volunteers, staff and managers for the event.

A comma should never sit directly after 'and' inside a list — it belongs before the conjunction, not after it.

Oxford comma in IELTS

Grammatical Range and Accuracy is 25% of your Speaking and Writing scores — here is where this structure earns marks.

Speaking

  • Long spoken lists ('I enjoy hiking, cycling, and reading') naturally include a short pause before the final item — that pause is the spoken version of the Oxford comma, and it helps the examiner follow a longer list clearly.
  • Either listing style is fine in Speaking; what examiners actually listen for is that you can produce longer, well-organised lists at all — a marker of lexical and grammatical range.

Writing

  • Choose one list style — with or without the Oxford comma — at the start of your Task 2 essay and use it throughout; consistency is what Grammatical Range and Accuracy rewards, not the choice itself.
  • In Task 1, lists of data categories ('imports, exports, and re-exports') benefit from the Oxford comma whenever the category names could otherwise blur together, improving clarity for the reader.

Practise oxford comma now

Five quick questions with instant feedback — every answer explained. No sign-up needed.

Question 1 of 5

Complete the two-item list correctly, with no comma before 'and': The museum is free for students ___ senior citizens.

Want the full set? All 12 oxford comma exercises →

Check this rule in your own writing

Reading a rule is step one; seeing it in your own sentences is what changes your band score.

Paste a paragraph into the free IELTS Grammar Checker — it flags every oxford comma mistake, explains the rule, and estimates your Grammatical Range & Accuracy band.

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Frequently asked questions

What is the Oxford comma?
The Oxford comma (or serial comma) is the comma placed before 'and' or 'or' at the end of a list of three or more items, as in 'red, white, and blue'. Leaving it out — 'red, white and blue' — is equally correct standard English.
Is the Oxford comma required in British English?
No. British English uses it less consistently than some American style guides, but neither using nor omitting it is a grammar error in either variety. The only rule is to stay consistent within one piece of writing.
Does IELTS prefer the Oxford comma?
No, IELTS accepts both styles. Examiners assess whether your punctuation is accurate and consistent, not which convention you choose for list commas.
When does the Oxford comma actually matter?
It matters when a list could be misread without it — for example, when the last two items could be mistaken for a description of an earlier item. In those specific cases, adding the comma removes the ambiguity, even if you don't use it everywhere else.
Does a list of two items ever need an Oxford comma?
No. The Oxford comma only applies to lists of three or more items. A two-item list joined by 'and' or 'or' never takes a comma before the conjunction, in any style.

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