1. In English, the two indefinite articles are a and an. Like other articles, indefinite articles are invariable. You use one or the other, depending on the first letter of the word following the article, for pronunciation reasons.
2. Article ¨AN¨ :Use an when the next word starts with a vowel (a,e,i,o,u) or with a mute h.
2.1. EXAMPLES OF AN
2.2. 1-AN ORNAMENT
2.3. 2-AN OBJECT
2.4. 3-AN ORBE
2.5. 4-AN OLD MAN
2.6. 5-AN UGLY PERSON
3. Article ¨A¨:Use a when the next word starts with a consonant, or before words starting in u and eu when they sound like you.