Capitalization in English

When to capitalize

Capital letters are used:

1. at the beginning of a sentence. This in printing is known as sentence case, where the first letter of the sentence is capitalized, and all others are lower case with the exception of proper nouns. In printing normal sentence case may be substituted by UPPER CASE (all letters are capitalized), and Title Case (where the first letter of each word is capitalized). Capitals are usually not used after a colon.
2. with some nouns and adjectives, usually if a noun indicates a proper noun.
3. pronoun "I".
4. personal and place names: "John", "Mr. Smith", "Amsterdam", "Europe", "Mount Everest", "the Ganges".
5. compass directions when referring to geographical regions: "Western Canada", "I was raised in the South", but not for points on a compass: "London is west of Paris"
6. national and regional adjectives: "an American" (noun), "an American man" (adjective).
7. religions: "a Catholic church" (adjective).
8. deities and personifications: "God", "Fame".
9. days, months: "Monday", "January", but not seasons such as "autumn"
10. brand names: "Toyota", "Nike", "Coca-Cola", unless the brand itself is purposely not capitalized: "iPhone", eBay".
11. royal titles: "King George III" but "kings and queens of England", but only sometimes 'sir' or 'madam'
12. planets and other celestial bodies: "Jupiter, the Crab Nebula", but not "the earth", "the sun", or "the moon"
13. Words which change their meaning between capitalized and uncapitalized usage, such as "liberal" and "Liberal", are called capitonyms: compare "A man of liberal tastes" and "The leader of the Liberal Party".
14. In legal documents, where the full name of an individual or body is later referred to in short form, in order to avoid ambiguity: "John C. Smith (Plaintiff)", "Exxon-Mobil Corporation (the Company)".

Capitalization of multi-word place names, institutions and titles of works

English usage is not consistent, but generally prepositions and articles are not capitalized: "the Forest of Dean", "Gone with the Wind", "University of Southampton". With some publications the "The" forms part of the title: "reading The Times". For a more detailed explanation see Capitalization § Titles.

Capitalization of acronyms and initialisms

Generally acronyms and initialisms are capitalized, e.g., "NASA" or "SOS." In British English, only the initial letter of an acronym is capitalized if the acronym is read as a word, e.g., "Unesco."