A and An

A or an can be precede only singular count nouns; they mean one. They can be used in a general statement or to introduce a subject which has not been previously mentioned.

1. A baseball is round.
(general—means all baseballs)

2. I saw a boy in the street.
(We don’t know which boy)

An is used before words that begin with a vowel sound. A is used before words that begin with a consonant sound.

Example:

A book an apple

Some words can be confusing because the spelling does not indicate the pronunciation.

A house (begins with a consonant sound)

An hour (begins with a vowel sound)

A university (begins with a consonant sound)

An umbrella (begins with a vowel sound)

The following words begin with a consonant sound and thus must always be precede by a.

European; eulogy; euphemism; eucalyptus;

house; home; heavy; half;

uniform; university; universal; union

The following words begin with a vowel sound and thus must always be precede by an.

hour; heir; herbal; honor;

uncle; umbrella; unnatural; understanding

the initial sound of the word that immediately follows the indefinite article will determine whether it should be a or an.

an umbrella; a white umbrella

an hour; a white hour

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