Indefinite Articles

1. "a" Article

1.1. Uses

1.1.1. When the next word starts with a consonant, or before words starting in u and eu when they sound like "you".

1.1.1.1. Example: A book, A hat

2. "an" Article

2.1. Uses

2.1.1. when the next word starts with a vowel (a,e,i,o,u) or with a mute h.

2.1.1.1. Example: An Apple, An octopus

3. Rules

3.1. Use a/an with names of jobs.

3.1.1. Example: An Architect, A lawyer

3.2. Use a/an with nationalities and religions in the singular.

3.2.1. Example: An Australian, A Catholic

3.3. Use a/an with the names of days of the week when not referring to any particular day.

3.3.1. I was born on a Thursday, I will come to your home on a Saturday

3.4. Use a/an to refer to an example of something.

3.4.1. It was a very strange car, He has an awesome house

3.5. Use a/an with singular nouns after the words 'what' and 'such'.

3.5.1. What a lovely day!, Such an awesome dinner!