Indefinite Articles Table

Indefinite Articles 'A' And 'An'
To Remember	Examples
'A/An' is used before Singular Countable Noun. A Noun which can be counted.	An Artist, A doctor, A boy, A dog, An umbrella
'A/An' is used before singular noun. It is not used before plural noun.	A book' is correct, 'a books' is incorrect as word 'books' is plural.
'A/An' is not used before proper noun, but when it is unknown for the speaker, 'A/An' is used.	This book is written by a Mukesh Ailawadi. (Here Ailawadi is an unknown person for the speaker)
'A/An' is used after what, such in exclamatory sentences.	What a scene, What a lovely boy, Such a big hall.
'A/An' is used when someone is introduced by features or personality of important/famous persons.	He is a Dara Singh of our colony, She is a Hitler, She is a Lata Mangeshkar of our college.
'A/An' is used before a verb which is used as a noun in a sentence.	We go for a walk daily, We had a long discussion, She wants to have a bath.
'A/An' is used after words -many/rather/quite/such, if it come before singular noun.	Many a times, quite an easy question, such an intelligent boy, rather a lovely place
If Adjective comes before singular noun, then 'A/An' is used before Adjective.	She is a beautiful girl, He is not a good person, He is an intelligent boy, She is an honest minister.
Before a singular noun which refers to a class of things.	An orange is rich in vitamins, A dog is an animal, A parrot is a bird, I am a journalist, She is an Indian.
'A/An' is used for certain expressions of quantity and numbers.	A lot of things, A few samples, A couple of days, A hundred rupee note, A million dollar question.
'A/An' is used before professions.	She is a teacher. He is an engineer. He is a manager. Ram is an MP.