Rule: A / An / Some / Any ShowHide

a or an

For one thing.

• an before a vowel sound (a, e, i, o, u): an apple, an egg, an igloo, an old car, an umbrella
• a before other sounds: a dog, a box, a parrot

Countable or uncountable

• Countable – you can count them one by one: an apple, two apples, a pencil, three eggs.
• Uncountable – you can't count them: water, milk, sugar, bread, cheese, money.

Uncountable nouns take no a or an and no -s.

some or any

• some in positive sentences: There is some snow on the roof. I've got some apples.
• any in negatives and questions: We don't have any sugar. Are there any eggs?

Asking about one thing you can count? Use a or an: Is there a park near here?