Are there any exceptions in indefinite articles?

Use 'a' when the word starts with a consonant, or before words starting in u and eu when they sound like you. Use an when the next word starts with a vowel or with a mute 'h'. For example:

Ø  She saw a big elephant in the park.

Ø  She needs an umbrella as it's raining outside.

Ø  It is a

Following are some books students can refer to for studying indefinite articles: 

In English grammar, articles are words that precede and modify nouns. They indicate whether a noun is specific or general. The definite article, "the," refers to a specific, known noun, while the indefinite articles, "a" and "an," refer to a general or unspecified noun.

Find below ten examples of articles:

1. I saw a cat in the balcony.
2. She wants to buy a house.
3. Can I have a bottle of juice, please?
4. He is an engineering at some big tech firm.
5. We had an antique vase in our living room.
6. I had an icecream for dinner.
7. The sun rises in the east.
8. She went to th

In English grammar, articles are words to come before a noun and indicate whether the noun is specific or general. The definite article (the) is used while talking about a specific noun. Whereas, indefinite articles (a, an) are used for general nouns or a noun whose indentity remains unknown.