How do you know whether to use "a" or "an"?

A and an are two different forms of the same word: the indefinite article a that is used before noun phrases. Use a when the noun or adjective that comes next begins with a consonant sound. Use an when the noun or adjective that comes next begins with a vowel sound. Remember that what matters is the pronunciation, not the spelling.

Here are some examples of the article a followed by words that begin with consonant sounds. In two cases the word after a starts with vowel letter, but the pronunciation still begins with a consonant sound.

• a football
• a driver’s license
• a European country (European begins with the vowel letter e, but the sound y.)
• a menu
• a university president (University begins with the vowel letter u, but the sound y.)

Here are some examples of the article an followed by words that begin with vowel sounds. Notice that in two cases, the word after an starts with a consonant letter, but the pronunciation still begins with a vowel sound.

• an apple
• an irritated driver
• an hour (Hour begins with the consonant letter h, but the h is silent.)
• an accurate weather report
• an MBA degree (MBA begins with the consonant letter M, but the M is pronounced with its letter name, "em.")