An article (abbreviated ART) is a word (or prefix or suffix) that is used with a noun to indicate the type of reference being made by the noun (Article, 2014).
HOW DO WE USE ARTICLES?
Used with countable nouns such as chair, dog, cat, pencil, bottle, etc.
We don’t use indefinite articles in front of non-countable nouns. These include abstract concepts such as happiness, harmony, sadness, irony, justice, etc.
The definite article can be used if indicating the instance in which it occurred: “The sadness she felt at his passing”
We don’t use indefinite articles with nouns that are described in quantities, such as liquids or large amounts of small solids such as beans, sand, dirt, etc. We can, however, use the definite article: “The brown dirt,” “the cold water,” etc.
Names, pronouns, and proper nouns
When being general: “I like water” (any/all water) “Cats are small” (any/all cats)
Example: “The Clear Lake that I know has lots of good restaurants;” (instead of “the place”) “You are not behaving like the Brandon that I know.” (instead of “the person”)
HOW TO DECIDE IN YOUR OWN WRITING
First, look at your noun. Is it countable or non countable?
Example: “I want to describe a cat. ‘Cat’ is a countable noun.”
STEP TWO:
Next, decide if it is the first time something has been mentioned.
If it is, use the indefinite article.
STEP THREE:
Are you being specific about the noun, or general?
Example: “Yes; I am talking about a specific cat.”
STEP FOUR:
If you are describing a specific noun, use the definite article. If you are being more vague, use the indefinite article.
Example: “I have a black cat. The cat chased the grey mouse.”
Example with indefinite article: “I saw a cat chase a mouse today.”
REFERENCES
Article (grammar). (n.d.). Retrieved November 24, 2014 from Wikipedia: http://en.wikipedia.org/wiki/Article_%28grammar%29