Capitalize the first word of a sentence, the pronoun I, and proper nouns: the names of specific people, places, brands, days, months, holidays, languages, and nationalities. Ordinary nouns such as city or cat stay in lowercase unless they start a sentence.
Knowing when to capitalize a word seems easy until you look at it in detail. That is where it can get confusing. Correct capitalization will not improve the content of your writing, but it does change how readers see it, and you want to make a good impression. Here are the rules of capitalization that matter most.
The basic rules
You probably remember many of these rules from school. Always capitalize:
- The pronoun I. Why English does this is a story of its own: see why "I" is capitalized in English.
- The first word of a sentence.
- Calendar items: the days of the week, the months, and holidays, including religious holidays: Monday, July, Thanksgiving, Easter. The seasons are not capitalized: summer, winter.
- The first word of the greeting and of the closing in a letter or email: Dear Anna, Sincerely yours.
- Languages, nationalities, and peoples: French, Swedish, Swedes, Native American.
- Religions, their followers, and the names of gods and holy books: Christianity, Christian, Muslim, God, Allah, the Bible.
- The names of specific courses: I'm taking Literature 203, but I'm taking a literature course.
- Brand names and company names.
- Titles of books, films, songs, and articles. In title case, you capitalize the first word, the last word, and all "important" words. Short words such as articles (a, an, the), short prepositions (to, on, by), and short conjunctions (and, but, or) usually stay in lowercase: The Lord of the Rings.
Style guides differ on the details of titles, for example on how long a preposition must be before it gets a capital. Pick one style and use it consistently.
The trickier rules
After these, the rules of capitalization get a little harder. They are still clear, but many people find them harder to remember.
Proper nouns
A common noun names any person, place, or thing, so it is not capitalized. A proper noun names one specific person, place, or thing, so it is.
| Common noun | Proper noun |
|---|---|
| restaurant | McDonald's |
| cat | Garfield |
| city | Las Vegas |
| mountains | Rocky Mountains |
Titles of people
Capitalize a title when it comes before a person's name. When it follows the name or stands on its own, it stays in lowercase:
- Uncle Bob, but Bob, my uncle
- Senator Flynn, but Mrs. Flynn, the senator
Direct quotations
Capitalize the first word of a direct quotation. If the quotation is split in the middle of a sentence, the second part does not start with a capital:
Bob said, "Yes, we would like to go."
"Yes," Bob said, "we would like to go."
What a spell checker can and cannot do
A spell checker can catch some capitalization mistakes for you, such as a sentence that starts with a small letter. No spell checker catches all of them, though.
Proper nouns cause the most trouble. A spell checker knows many common names, but it cannot know every name there is. The more unusual a name, the less likely a spell checker is to recognize it and check its capital letter. Some names are ordinary words as well: bob and rocky are correct in lowercase in one sentence and need a capital in another.
That is why you need a basic understanding of the rules of capitalization yourself. A spell checker such as the Spell Checker finds many of your mistakes, but the rest are up to you.