indefinite article

If you are using an indefinite article ( “a” or “an”), you have to decide which one to choose based on the sound of the word after.

“a” is used with consonant sounds and “an” is used with vowel sounds.

Examples:
“a”
I bought a bike.
I have a yogurt.
Tony bought a used car.
They built a university near my house.
(A word beginning in “u” sometimes sounds like it begins with “y” which is a consonant sound, therefore you will need to use “a” instead of “an”.

“an”
I have an idea.
I have an ugly sister.