Important Words aren’t Capitalized for the Hell of It.
Here’s the basic run-down:
1. The first word in each sentence is capitalize–but you know that already.
2. In formal titles, the first word and each word longer than two letters (minus words like “the,” “and,” “but,” etc)
Example: How to Annoy Your Readers by Adding Random Capitalized Words
3. In informal titles, only the first word and proper nouns are capitalized.
Example: How to bestselling book in one weekend–thanks to NoDoz!
NoDoz is a proper noun, so it’s capitalized; How starts the sentence, so it remains capitalized, but none of the other words are, even though they’re in a title.
There are few rules dictating whether you use formal or informal titles. This is largely a matter of in-house style. I personally like formal titles, but many online newspapers and blogs have moved to informal style, like The Examiner.
4. Days of the week, months, states, countries, proper names are always capitalized.
Monday, January, Texas, Uganda, Johnny Depp
5. Proper nouns (an extension of Rule 4) are always capitalized. These are formal, official titles for things.
Captain Jack, the Microsoft corporation, Barnes & Noble, Aunt Betty.
6. Non-noun words are only capitalized if they’re in a formal title, starting a sentence, or part of a proper noun phrase. It doesn’t matter how important the modifier is, you’re not Emily Dickinson or ee cummings–they aren’t capitalized. Same goes for plain old nouns–their importance doesn’t matter.
Incorrect: The Purple Throne beckoned me to Sit in it; The Man Spanked her so hard she had a Handprint on her Ass.
Correct: The sun shone off the dark windows of the Hustler store; The experienced Dom brought his floggers and crops to Maison Domine for the weekend.
6. Words that are capitalized depending on the situation are the most challenging. The most frequent examples I come across occur when a word is used in place of someone’s formal name, like Mother instead of Deborah. But you only capitalize the word when you could use the proper name in place of the nickname and have the sentence still be accurate.
Incorrect: I refuse to let my Mother read my books. [I refuse to let my Deborah read the books doesn’t make sense, so Mother shouldn’t be capitalized]
Correct: “Guess what, Mother, I’m sending you on a trip to Europe because my royalty checks were huge this summer!” (yeah, don’t we all wish). Here, you could just as easily say, “Guess what, Deborah, I’m sending you…” so the capitalization is correct.