The rules for proper nouns are more complex than those for common nouns.

Proper nouns are names of particular people, places, and things, eg.

John F. Kennedy,

New York City,

Notre Dame Cathedral,

and for that reason they are inherently definite.

However,

• the definite article is not used with most singular proper nouns.

For example,
if you are referring to your friend George, you wouldn't say "The George and I went to a movie last night."

• The only times "the" is used with a name like this are:

a) when you want to be emphatic, as in "the Elizabeth Taylor" (to emphasize that you are talking about the famous actress, and not about another woman with the same name)

b) when you are actually using the name as a common noun, as in "the George that I introduced you to last night" (the real meaning of this phrase is the man named George...").

c) Plural names, on the other hand, are always preceded by "the": the Johnsons, the Bahamas, etc.

• Singular geographical names are very irregular with respect to article usage.

For example,

a) singular names of continents (Asia, Africa), mountains (Mount Fuji), and bays (San Francisco Bay) do not take the article "the,"

b) but regions (the Crimea), deserts (the Sahara), and other geographical entities do.

• The use of articles with singular proper nouns is complex and hence difficult to learn, as indicated by the examples below. For this reason, the best thing to do is to memorize whether the proper nouns that you use frequently are used with or without "the."

Examples:

State Street
the Empire State Building
Delaware County
Great Britain
the Soviet Union
the University of Virginia
Rensselaer Polytechnic Institute
the United Nations (the U.N.)
the Organization of Petroleum Exporting Countries (but "OPEC," not "the OPEC")