Basics Rules for Using Capital Letters in Writing
In formal writing you don’t want to sprinkle caps in indiscriminately, nor do you want to neglect to cap proper nouns and names that should be capped. English rules for using capital letters aren’t all that logical, but they are pretty easy. Here are the basics:
Begin every sentence with a capital letter: What’s that you asked? What about sentences that begin with a numeral? Caught you! You’re not supposed to begin a sentence with a numeral. Ever. If a number is needed in that spot, you have to write the word and capitalize it. So if you’re a star pitcher and the Yankees make an offer, don’t send this text: $10,000,000 per game is not enough.
Instead, type one of these messages:
A mere $10,000,000 per game is not enough.
Ten million dollars per game is not enough.
Traditionally, the first letter of each line of a poem is capitalized, even if it isn’t the beginning of a sentence. However, poets enjoy trashing (sorry, I meant reinterpreting) rules. In poetry, anything goes, including capitalization rules.
Capitalize I: There is no logical reason why the personal pronoun I — the word you use to refer to yourself — must be capitalized. The reason probably has something to do with psychology. So go for caps when you write I, and save lowercase for other pronouns (he, she, us, them, and so on).
Capitalize names: This rule applies when you’re using an actual name, not a category. Write about Elizabeth, not elizabeth, when you’re discussing the cutest baby ever (my granddaughter). She’s a girl, not a Girl, because girl is a category, not a name. Elizabeth lives in Washington, not washington (her state, not State, because state is a general category, not a name). You also capitalize brand names (Sony, for example) unless the company itself uses lowercase letters (the iPod, for instance).
Capitalize words that refer to the deity: Traditionally, believers capitalize all words that refer to the being they worship, as in this line from a famous hymn:
God works in mysterious ways His wonders to perform.
Capitalize mythological gods only when giving their names:
The ancient Greeks built temples in honor of Zeus and other gods.
Begin most quotations with a capital letter: When quotation marks appear, so do capital letters — most of the time.