Understanding the Indefinite Articles A/An: The Importance of Word Sounds in English

When you were a beginner student of English, you learned that the article ‘an’ goes before vowels (a, e, i, o, u), and the article ‘a’ goes before consonants (letters that are not vowels), like t, r, v, etc.

That’s a good general rule, but it’s not really true.

Look at this sentence for example: I have an uncle who works at a university. I will meet him in an hour.

So, why is it ‘an’ uncle but “a” university? And why ‘an’ before hour?? The answer is: word sounds.

Articles A/An: Sound is More Important than Spelling

Let’s think about it. How do you say the word uncle? It’s pronounced /ˈʌŋk(ə)l/ (or ‘un-kl’). This is a vowel sound (starting with ‘u’), so we need to use the article ‘an’.

How do you pronounce university? It’s pronounced /juːnɪˈvəːsɪti/( or “you-ni-ver-sity”). This is actually a consonant sound (starting with a ‘y’). So, we use the article ‘a’.

How to you pronounce hour? If you pronounce it correctly, you know that the ‘h’ is silent. The correct pronunciation is /’aʊə/ (or “our”). This means the first sound is an ‘o’ sound — a vowel sound! So, you need to use “an” because the first sound is an ‘o’.

The real rule for the indefinite articles a/an: ‘An’ is used for words with a vowel sound (like apple, ear, and hour); ‘a’ is used for consonant sounds (like fox, pig, and university).

Using the Indefinite Articles A/An with Abbreviations & Acronyms

Now, this rule is very important when you use abbreviations (shortened words, such as “Dr.”) and acronyms (words like “USA”, in which each letter stands for a word (United States of America)).

Here’s are two example sentences. Fill in the article ‘a’ or ‘an’:

My sister has M.A. in English. Yesterday, she sent me SMS from her new mobile phone.

Here are the correct sentences:

The rules are the same. “M.A.” is pronounced “emm aye”, so it’s a vowel sound. “SMS” is pronounced “ess-emm-ess”, so it’s also a vowel sound.

The Indefinite Articles A/An: Practice Exercises

Do you think you understand? Try these indefinite article exercises.

Helpful hint: As a rule, you can remember that abbreviations or acronyms that use ‘an’ start with these letters: A, E, F, H, I L, M, N, O, S, X
I hope this has been helpful. Using English articles correctly is not easy. Many native English speakers make mistakes with indefinite articles. Articles are difficult to use correctly, but they are important if you want to communicate in English without errors.

Good luck!

Related Lessons:

• Article Practice Exercises (All Levels)
• Help Understanding Articles (Beginner)
• The Definite Article with Names of Places (Advanced)

– Matthew Barton / Englishcurrent.com (Copyright)