- A white house on a green hill.
- A cat ate the sardine
* We are not specifying which cat ate the sardine, it could have been any cat.
It is normal to use the indefinite article when we mention someone or something for the first time in our conversation or text.
- I've finally got a good job.
- We bought a new computer and it was cheap.
- Would you like a drink?
"A" and "an" are also used to refer to a particular member of a group or class.
- She is an English teacher.
- He wants to be a dancer.
- John is an Englishman.
- Sherlock Holmes was playing a violin when the visitor arrived.
- I was born on a Thursday.
We also use the indefinite article to talk about price / weight, speed.
- This car does 240 km an hour.
- It is 10 euros a kilo.
Certain numbers in English require the presence of an indefinite article.
- A hundred, a thousand, a million, etc...
With singular nouns, after the words "what" and "such"
- What a day!
- What a shame!
- She's such a beautiful girl.
Meaning "one", referring to a single object or person
- I'd like an orange and two lemons please.
- The burglar took a diamond necklace and a valuable painting.
The choice between "a" and "an"
Depends on the initial sound of the adjective that immediately follows the article:
Use "a" with nouns starting with a consonant. On the other hand, we use "an" before nouns starting with a vowel.
- an umbrella
- a table
- an elephant
- a book
NOTE: If the next word begins with a consonant sound when we say it then we use a. If the next word begins with a vowel sound when we say it then we use an.
- We say "university" with a "y" sound at the beginning as though it were spelt "youniversity".
=> a university
- We say "hour" with a silent h as though it were spelt "our".
=> an hour