Definite and Indefinite articles English Grammar

1. We use the indefinite article, a or an when we do not know exactly which one we are referring to:

For example:
Police are searching for a ten year-old girl.

2. We also use it to show the person or thing is one of a group:

For example:
She is a student at Oxford University.

3. What is the difference between A and AN?

A is used when the next word begins with a consonant sound (b, c, d, f, g, h, j, k etc).
• a book
• a table
• a clock
• a university (because the beginning of university sounds like YOU-niversity)

AN is used when the next word begins with a vowel sound (a, e, i, o, u).
• an apple
• an elephant
• an umbrella
• an hour (because the H is silent)

4. A and AN can only be used with singular nouns.

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