If you are not sure what article to use with a noun, use the basic questions on the following chart as a guide. 

Questions					Guides				Examples
1. Common/Proper: Is it a common noun or a proper noun?
		It is a PROPER NOUN					Singular uses no article		Example: Tom Smith is here with his wife.
							Plural uses the		Example: The Smiths are here.
		*But be careful with proper nouns: there are many exceptions.  See below.
It is a COMMON NOUN
2. General/ Specific: Does the reader know which thing(s) you mean?		YES, the reader knows (specific)				Singular uses the			Examples: The sun is bright. Jack caught a cold. The cold lasted two weeks.
						Plural uses the			Example: I like the shoes you are wearing
No, the reader does not know (general)
3. Count/ Non-Count: Can the noun be counted in English?		YES, it is countable				Singular uses a, an			Example: Frank bought a new car with an old engine.
						Plural uses no article			Example: Books can be fun to read.
NO, it is not countable (It is a Non-Count Noun)
		Non-Count Nouns use no article, or use the word some							Example: Americans enjoy freedom and liberty.
									Example: I would like some water.

There are several exceptions, or more complicated situations than the above chart covers.  Below we have laid out some of the general and specific rules about using A, AN, and THE. 

Remember, in order to use A, AN, and THE properly, you must know whether or not a noun is a Count or Non-Count Noun.  (A count noun is the name of something that can be counted: one book, two books, three books.  A non-count noun is the name of something that cannot be counted: milk, flour, freedom, justice).

 

	Use "a" or "an"	Use "the"	Don't Use "a," "an," or "the"
General Rules	Use "a" or "an" with a singular count noun when you mean "one of many," "any," "in general." Bob is a student (one of many students). I like a good movie (one of many movies).	Use "the" with any noun when the meaning is specific; for example, when the noun names the only one (or one) of a kind. Adam was the first man (the only 'first man'). New York is the largest city in the United States (only one city can be 'the largest'). We live on the earth (the only Earth we know). Have you heard the news (specific news)?	Don't Use "a," "an," or "the" with a non-count noun when you mean "any," "in general." We believe in love (in general). He gave me information (not specific).
	Use "a" or "an" the first time you use a noun in a paragraph I saw a movie last night. A man ran into the street.	Use "the" the second time you use that same noun in the same paragraph I saw a movie last night. The movie was entertaining. A man ran into the street. A car hit the man.	Don't Use "a," "an," or "the" with a plural count noun when you mean "some of many things," "any," "in general." Movies are entertaining (some movies; movies in general). She likes men (in general).
Title	Use "a" or "an" if the title is not a specific title. a president a doctor a queen	Use "the" if a specific person has a title or if only one person has a title. the president the doctor the Queen of England	Don't Use "a," "an," or "the" if the person's name is given. President Kennedy Dr. Yang Queen Elizabeth
Names of Countries	Non-specific a country	Use "the" if the name of the country is plural or indicates a group (of states, islands, etc.) the United States the Netherlands the Phillipines	Don't Use "a," "an," or "the" Russia South Africa Holland Canada Great Britian England
Names of Continents	Non-specific a continent		Don't Use "a," "an," or "the" Africa Asia Europe North America
Names of Some Geographical Areas		Use "the" the South Pole the West the South the North East	Don't Use "a," "an," or "the" Western Europe
Names of Cities and States	Non-specific a city a state		Don't Use "a," "an," or "the" New York Paris Washington Exception: the District of Columbia
Names of Streets			Don't Use "a," "an," or "the" Pennsylvania Avenue Fourth Street Florida Avenue
Names of Oceans, Rivers, Seas, Deserts, Forests, Canals	Use a/an for non-specific an ocean a river a sea a desert	Use "the" the Pacific Ocean the Mediteranean Sea the Potomac River the C & O Canal the Atlantic Ocean the Painted Desert
Names of Lakes	Non-specific a lake		Don't Use "a," "an," or "the" Lake Ontario Lake Geneva
Names of Monuments, Memorials, Parks, and National Shrines	Use a/an if you write about a non-specific building or monument. a building a museum an institution	Use "the" the Capitol the White House the Senate Office Building the Sam Rayburn Building the National Archives the Library of Congress the National Gallery of Art the Smithsonian Institute
Names of Colleges, Universities, and Other Schools	Use a/an for non-specific colleges or schools. a school a university	Use "the" if the title of the school has "of" or "for" in it. the University of Maryland the Catholic University of America the Maryland School for the Deaf The Model Secondary School for the Deaf	Don't Use "a," "an," or "the" if the school is named for a person or place. Gallaudet University Harvard University George Washinton University Georgetown University Maryland University Catholic University
Names of Buildings on Gallaudet University Campus	Use a/an for non-specific buildings a dorm an office	Use the with specific places that have no names. the infirmary the library the dorm the cafeteria the bookstore	Don't Use "a," "an," or "the" if a building on campus is named for a person. Peet Hall Ely Center Dawes House Krug Hall Hall Memorial Building Hughes Gymnasium Merrill Learning Center Kendall School