a ولا an?

[ابو بيشو]

How do you know when to use the indefinite articles?

"A" goes before all words that begin with consonants.

• a cat
• a dog
• a purple onion
• a buffalo
• a big apple

With one exception: Use "an" before unsounded h.

• an honorable peace
• an honest error

"An" goes before all words that begin with vowels:

• an apricot
• an egg
• an Indian
• an orbit
• an uprising

With two exceptions: When u makes the same sound as the y in you, or o makes the same sound as w in won, then a is used.

• a union
• a united front
• a unicorn
• a used napkin
• a U.S. ship
• a one-legged man

Note: The choice of article is actually based upon the phonetic (sound) quality of the first letter in a word, not on the orthographic (written) representation of the letter. If the first letter makes a vowel-type sound, you use "an"; if the first letter would make a consonant-type sound, you use "a." So, if you consider the rule from a phonetic perspective, there aren't any exceptions. Since the 'h' hasn't any phonetic representation, no audible sound, in the first exception, the sound that follows the article is a vowel; consequently, 'an' is used. In the second exception, the word-initial 'y' sound (unicorn) is actually a glide [j] phonetically, which has consonantal properties; consequently, it is treated as a consonant, requiring 'a'.