Rule 1:
In the singular sequence, a common noun also has an article prior to it. But an article doesn’t necessarily need a traditional plural noun. A plural common noun will have the article ‘the’ if we want to designate the noun.
Example:
- I have an apple. (Refers to a random apple)
- I ate pinapple at home. (No article is required)
- I have eaten the apples again (Refers to the apple i have eaten earlier)
- I have eaten the apples again before leaving the house. (Refers to the particular apples which I ate earlier at the house.)
Rule 2:
You can choose between the two indefinite articles – a & an – by its sound. There are some exceptional cases against the general use of ‘a’ and ‘an’
- a university, a union, a useful book, etc.
- a one-dollar book, a one-man army, etc.
- an MA, a BA, an LLB, a BSC, etc.
Rule 3:
A or an – sometimes a sentence can translate a Proper noun into Common noun. Proper nouns are generally not preceded by articles but when it changes to common noun it needs an article.
Example:
- He regards himself as a Shakespeare. (Here, Shakespeare isn’t the person but a reference)
- She thinks her house is a Palace.
Rule 4:
We use indefinite articles to represent a number that is generally ‘one’/’each’/’per’.
Example:
- I am half an hour late for the meeting. (Half an hour late)
- I have a dog. (One dog)
- The plane can travel 10 miles an minute ( an hour or per hour)
Rule 5:
Indefinite articles are often used before any descriptive adjectives.
Example:
- He is a good boy.
- What a nice car !
- She is a brilliant student.
Rule 6:
‘A’ sometimes precede determiners, for example, a few, a little, a lot of, a most, etc.
However, when you write a sentence using many, ‘a’ or ‘an’ is used after it.
Example:
- I have a few pens lying around on the table.
- There is a little water in the bottle
- Many a man tried to rescue the dog, but none could.