
Rule 1: Start of a sentence
Always capitalize the first word of every sentence.
Rule 2: Proper nouns (names, places, brands, organizations)
Capitalize specific people, places, organizations, and brands.
Rule 3: Days, months, holidays (not seasons)
Capitalize days, months, and holidays. Seasons (spring, summer) are lowercase.
Rule 4: Titles of works, honorifics, job titles before names
Capitalize major words in titles and professional titles before a name.
Rule 5: The pronoun “I” and the interjection “O”
Always capitalize “I” no matter where it appears. Capitalize the poetic “O.”
Rule 6: After a colon (if a full sentence) and in salutations
Capitalize after a colon when a complete sentence follows. Also capitalize salutations/closings.
Rule 7: Languages, nationalities, proper adjectives
Capitalize languages, countries, and adjectives derived from proper nouns.
Rule 8: Historical periods, events, trademarks
Capitalize specific historical eras, named events, and brand/trademark names.