Grammar · Nouns, articles & agreement · A1 · Beginner

A vs an

Last updated 21 July 2026

In short

Choose a or an based on the sound of the next word, not its spelling. Use an before a vowel sound (an apple, an hour, an MBA) and a before a consonant sound (a university, a one-way ticket, a European city). Silent letters and letter names are the main traps, because spelling and pronunciation disagree.

A vs an at a glance

	A	An
Rule	Before a consonant sound	Before a vowel sound
Silent 'h' words	a house, a hotel (h is pronounced)	an hour, an honest mistake (h is silent)
'U'/'eu' words	a university, a European, a uniform (start with the /j/ 'y' sound)	an umbrella, an uncle (start with a true vowel sound)
Letters and acronyms	a NATO summit ('nay-toh', consonant sound)	an MBA, an FAQ, an SOS (letter names starting with a vowel sound)
Numbers	a one-off event (starts with a 'w' sound)	an eight-year-old (starts with a true vowel sound)

Why does sound decide 'a' or 'an', not spelling?

English chooses between a and an based on the sound at the start of the next word, not the letter it happens to be written with. Use an when that sound is a vowel sound, and a when it's a consonant sound — whatever the spelling looks like.

Most of the time spelling and sound agree, so a before consonant letters and an before vowel letters feels automatic. The rule only becomes visible — and only trips learners up — in the handful of cases below, where the first letter and the first sound disagree.

She ordered an omelette for breakfast.(spelling and sound agree — vowel letter, vowel sound)
He bought a bicycle for his daughter's birthday.(consonant letter, consonant sound)

The trickiest cases: silent 'h' and words starting with 'u'

A handful of words spelled with h actually begin with a vowel sound, because the h itself is silent: hour, honest, honour, heir. These always take an, even though the first letter is a consonant.

Words that start with the letter u cause the opposite problem: many of them — university, uniform, union, useful, European — actually begin with the consonant sound /j/ ('y' as in yes), so they take a, not an, despite the vowel spelling.

It took her almost an hour to finish the assignment.(silent h → vowel sound)
He wore a uniform for his first day at the new job.('uniform' sounds like 'yoo-niform' → consonant sound)
That's an unique way to solve the problem.(→ a unique way — 'unique' starts with the /j/ sound)

Letters, acronyms and numbers

Spoken letter names follow the same sound rule. F, H, L, M, N, R, S and X are all pronounced starting with a vowel sound ('ef', 'aitch', 'el', 'em', 'en', 'ar', 'es', 'ex'), so abbreviations that begin with them take an: an FAQ, an HR manager, an SOS.

Numbers behave the same way when spoken aloud: 'one' starts with a 'w' sound, so it takes a ('a one-way ticket'), while 'eight' and 'eleven' start with true vowel sounds and take an ('an eight-year-old', 'an eleven-hour flight').

She's applying for an MBA at a university in Toronto.('M' is pronounced 'em')
It's a one-in-a-million opportunity.('one' sounds like 'won' — consonant sound)
We waited for a hour and a half at the immigration desk.(→ an hour and a half)

Common mistakes with a vs an

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

She works for an university in Manchester.

She works for a university in Manchester.

'University' begins with the consonant sound /j/ ('yoo'), so a is correct despite the vowel spelling.

He waited for a hour before the doctor called him in.

He waited for an hour before the doctor called him in.

The h in 'hour' is silent, so the word begins with a vowel sound and needs an.

I need an USB cable for my laptop.

I need a USB cable for my laptop.

'USB' starts with the letter U, spoken 'yoo' — a consonant sound — so a is correct.

It was a honest mistake, so the teacher didn't deduct any marks.

It was an honest mistake, so the teacher didn't deduct any marks.

The h in 'honest' is silent, so the word begins with a vowel sound and needs an.

He has a MBA from a well-known business school.

He has an MBA from a well-known business school.

The letter M is pronounced 'em', which starts with a vowel sound, so an is required.

I'm looking for an one-bedroom flat near the station.

I'm looking for a one-bedroom flat near the station.

'One' starts with a 'w' sound when spoken, so a is correct despite the vowel spelling.

A vs an in IELTS

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

Speaking

Article slips like 'an university' are among the fastest-noticed accuracy errors in Part 1 — examiners hear the vowel/consonant mismatch immediately, even in an otherwise fluent answer.
When you mention qualifications or job titles ('I have an MBA', 'she's a UN interpreter'), rehearse the sound aloud beforehand — abbreviations are the most common a/an trap in Part 3 discussions about work and study.

Writing

In Task 2 essays about education or technology, 'a university degree' and 'an online course' are both common phrases — check the sound of the noun immediately after a/an, not of an adjective that comes between them (an outdated system, but a useful system).
In Task 1, data commentary often needs a or an before numbers written as words ('an eighteen percent rise' vs 'a fifty percent fall') — say the number aloud to check its first sound before choosing the article.

Practise a vs an now

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Check this rule in your own writing

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Frequently asked questions

Do you use 'a' or 'an' before a word that starts with a vowel letter?

It depends on the sound, not the letter. Most vowel-letter words start with a vowel sound and take an ('an apple'), but a few, like 'university', start with a consonant sound and take a. Always say the word aloud and listen to its first sound.

Is it 'a MBA' or 'an MBA'?

An MBA — the letter M is pronounced 'em', which starts with a vowel sound. The rule follows pronunciation, so spoken letter names matter more than the written first letter.

Why do we say 'a university' if 'u' is a vowel?

Because 'university' starts with the consonant sound /j/ ('yoo'), not a true vowel sound, the a/an rule follows the sound and chooses a. The same logic applies to uniform, union, and European.

Is it 'a hour' or 'an hour'?

An hour — the h is silent, so the word actually begins with a vowel sound. Other silent-h words like honest and honour follow the same rule.

Do numbers like 'one' and 'eight' follow the same a/an rule?

Yes. 'A one-way ticket' takes a because 'one' starts with a 'w' sound, while 'an eight-hour flight' takes an because 'eight' starts with a true vowel sound. The spelling of the numeral is irrelevant — only the spoken sound counts.

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