Using Capital Letters (Proper Nouns and Common Nouns)

The Quick Answer
Do not use a capital letter for a common noun (i.e., the word for something) unless it starts a sentence. For example:
  • city
  • cat
  • ocean
  • uncle
  • tower
Do use a capital letter for a proper noun (i.e., the specific name of something). For example:
  • New York
  • Lucky
  • Pacific Ocean
  • Uncle George
  • Sears Tower

Capital Letters for Proper Nouns

Use capital letters for the names of people, places, planets, days of the week, titles of rank or relationship (when joined to person's name, e.g., Sergeant Smith, Uncle Fred), months, holidays, departments, clubs, companies, institutions, bridges, buildings, monuments, parks, ships, hotels, streets, historical events, and documents. These are known as proper nouns.)

Do not use a capital letter for a common noun, unless it starts a sentence. A common noun is the word we use for something, e.g., dog, ship, auntie. Common nouns contrast with proper nouns, which are specific names or titles, e.g., Rover, Titanic, Auntie Sally.

Video Summarizing Common and Proper Nouns

Here is a video summarizing the difference between common nouns and proper nouns:

Examples Showing When to Use Capital Letters

In the examples below, the proper nouns (i.e., the names or titles) are in bold.
  • The next lake the party visited was Lake Michigan.
  • (The word lake is a common noun. It is the word for an in-land water feature.
    Lake Michigan is a proper noun. It is the name of the lake.)
  • According to Lord Davies, The Church in London is not actually a church but a public house.
  • (The Church is a proper noun. The word church is a common noun.)
  • It was a rewarding day, and I intend to visit here again on Armistice Day next year.
  • (The word day is a common noun. Armistice Day is a proper noun.)
  • Could you ask Sergeant Allan or the other sergeant to arrange the patrol on Friday morning?
  • (Sergeant Allan is a proper noun. The word sergeant is a common noun.)

Big Fish should be big fish
(magazine article)

Toilet should be toilet
(instructions on packaging for a toilet seat)

See Also

What are nouns? The different types of nouns Capital letters in advertisements Capital letters and the points of the compass Capital letters with the four seasons Capital letters with moons, stars and planets Capital letters start sentences What is title case? Test on using capital letters