Everyone knows to capitalize words at the beginning of a sentence, and always to capitalize the pronoun “I” and names—but did you know that there are special cases for capitalization that many people are unaware of?  In this day of Internet slang and text message lingo, capitalization even in the most common cases has all but disappeared, so learning when capitalization is appropriate—and when it is not—can be difficult.

Words in a Title

"Capitalize your titles!" is something you’ve probably heard in school; but sometimes your spell checker will probably underscore certain words with a green, squiggly line telling you that the word is spelled incorrectly. This is because, unless the word is the first or last of the title, certain words are not capitalized.

Articles like "the" or "an," prepositions like "in" and "to," and conjunctions such as "and" and "or" need not be capitalized.  Conjunctions of five words or more such as "beyond" should be capitalized. Example: "Somewhere Beyond the Sea."

Titles

Titles are perhaps the most difficult to remember.

• Capitalization should always be used when a person’s title precedes their name. Example: If Corporal Brown is coming to visit your school to discuss safety procedures, you would always capitalize his title.

• Capitalization is unnecessary when simply the title is used. For example: If you want to express that “the corporal will be here at noon,” there is no need to capitalize the proper title.

Capitalization works this way because, when you use the title before the name, the title itself becomes a "part" of the name (that is, it becomes a part of the proper noun). When you state simply "the corporal," the title is a common noun, no longer a proper one.

Similarly, when you are referring to your mother and father, you need not capitalize it unless you are addressing them by the title.

• "My mother and father and father are coming over” is perfectly acceptable.

• I your refer to them by name you need to capitalize. "Mother called and explained that she and Father will likely be late.

Notice that in the first instance you would not be able to replace the terms "mother and father" with their names ("my George and Dana are coming over"), but in the second you would ("Dana called and explained that she and George would be late.").

When you are using the title to refer to a person of high importance, a similar rule follows.

• You would capitalize the term "president" when referring to the actual position, as in "Barack Obama is the President of the United States," or "President Obama stepped onto the plane."

• You would not, however, capitalize the title when discussing Obama’s "first term as president." This instance does not refer to the specific person or full title.

Directions

Some people are tempted to capitalize directions whenever they’re used.  “We traveled North, South, East and West!” seems like an appropriate use of capitalization.

There are special cases for direction capitalization, and the key rule to remember is that capitalization may only be used for directions when the direction that you’re using is specific; that is, a proper noun.

"We traveled from south to north along the entire East Coast" is appropriate, because "East Coast" is technically a proper noun referring to a specific place (notice, of course, how the word "coast" is also capitalized), but "south" and "north" are common, nonspecific nouns.

Unfortunately, the rules can become a bit confusing when referring to specific things or events.

• While "Northern Hemisphere" is capitalized, the "northern lights" refer to a nonspecific phenomenon, and are not.
• The southern and northern "polar lights", known as "polar auroras," are not capitalized, although the "North Magnetic Pole" is.

The next time you become confused over capitalization, check out these handy rules dealing with special cases for capitalization.