APPLICATIONS AND RULES FOR INDEFINITE ARTICLES
Antonio Torresにより
1. Example
1.1. an apple
1.2. an an actress
1.3. an ant
1.4. an ugly man
1.5. an ice cream
2. With "an"
2.1. When the word begins with a vowel (a, e, i, o, u), then you should use 'an'.
3. Example
3.1. a table
3.2. a chair
3.3. a house
3.4. a bed
3.5. a rose
4. With "a"
4.1. When the word begins with a consonant you must use 'a'.