According to Grammarbook.com, proper nouns are always capitalized. These are nouns that are both important and specific. For example, it is quickly evident that "White House" is a more important noun than "white house." The first is the home of the president, while the second could be any white house.
Common nouns describe general categories, such as "girl" or "state." These words could refer to any young female or any section of the United States. However, proper nouns pulled from these categories would need capitals; Susan and Alabama are examples.
Title case refers to a specific way to capitalize words in the title of a book, song, movie or anything that needs a title. The following title case rules are consistent with Associated Press style guidelines, which is one of the most common published styles used. However, there are no hard, universal rules for title case; the style of the title is ultimately up to the publisher.
Grammarbook.com states that the first word of a title must always be capitalized, along with being verbs such as "is," "are" and "were." All words important to the title must also be capitalized, including both proper and common nouns. Articles and conjunctions, such as "the, "and" and "or," are never capitalized. Prepositions shorter than five letters are never capitalized; examples are "of" and "with."
Some examples are: "We Were Soldiers" and "Harry Potter and the Prisoner of Azkaban."
Grammarbook.com says that titles that precede a person's name, such as "President Washington" or "Chairperson Smith" are capitalized. If that title comes after the person's name or stands alone, it is not capitalized. Examples include: "George Washington, the president, has arrived." And, "The chairperson will be 10 minutes late."
Titles in the address and signature line of a letter, whether they are before or after the name, are capitalized. For example "Joan Smith, Chairperson," is correct.
Names of classes are always capitalized when they are derived from a proper noun, according to Grammarbook.com. For example, "English," "German" and "Spanish" are all capitalized because they come from the names of their countries. Such names as "math" and "algebra" are not capitalized because they do not come from proper nouns.
Class titles are also capitalized if they are specific. While "algebra" is not capitalized, "Algebra II" must be because it is a specific class.
The first word of a sentence, according to Grammarbook.com, must always be capitalized. This, with punctuation, helps to separate sentences and makes them easier for the eye to follow. All proper nouns within a sentence must also be capitalized.
Words after a colon are not capitalized unless one or more sentences follow the colon. Phrases following a colon are never capitalized. For example, "Shakespeare was a great playwright: his prose was beautiful," is not capitalized. However, "Shakespeare was a great playwright: His prose was beautiful. He created many wonderful stories," includes a capital for each sentence.