Capitalization rules: When to use capital letters in English

English capitalization rules involve a lot more than just capitalizing the first letter of a sentence. 

Here we will go through when to use capital letters in English, including the various ways you can capitalize titles. We’ll cover all the potentially confusing capitalization rules regarding proper nouns, colons, and quotations.

We hope this helps clear up when to capitalize a word and when to stick with lowercase.

3 English capitalization rules

In English, we capitalize a word by writing the first letter in uppercase and the remaining letters in lowercase.

The three general rules of English capitalization dictate that you should always use a capital letter for:

1. The first word of a sentence
2. The pronoun ‘I’
3. Proper nouns

We will look at these first, and then go over some exceptions and specific questions around colons, titles, and quotations.

1. Capitalize the first word of a sentence

This is the most simple capitalization rule and you will see it in use throughout this document. Always capitalize the first letter of a sentence.

2. The pronoun ‘I’ is always capitalized

This capitalization rule is also quite straightforward: Whenever you use the first person singular pronoun ‘I’, it should be capitalized.

• I wish I could win the lottery.
• Jamie and I are going on a date tonight.
• Never have I ever been so embarrassed as when I spilled wine all over myself and the bride at a wedding.

As you can see, this rule applies regardless of whether ‘I’ appears as the first word in a sentence or part-way through it.

Unsure about when to use I, me, or myself? We have you covered.

3. Capitalize proper nouns and adjectives derived from them

Proper nouns and common nouns are a big topic, but we will go over the basics here in relation to using capital letters in writing.

A proper noun is a type of noun that refers to a specific place, person, or thing by name. Proper nouns should always be capitalized, as should any adjectives derived from them (also called ‘proper adjectives’).

Examples of proper nouns and adjectives include:

• Italy
• Italian
• William Shakespeare
• Shakespearian
• the Eiffel Tower
• the River Thames
• the Olympic Games

Proper nouns are the opposite of common nouns, which refer to places, people, or things in general – not specific names. Common nouns should not start with a capital letter unless they are the first word of a new sentence or part of a title.

Examples of common nouns include:

• country
• footballer
• poet
• tower
• city
• river
• tournament

Here’s a more detailed breakdown of proper nouns that we need to capitalize, with examples of each one:

• Names: Mr Smith; Roger Federer; Lady Gaga; Madonna; George W. Bush; Grandpa
• Continents, countries, states, cities, towns, regions: Africa; Thailand; Colorado; London; Wellington; the Midlands
• Landmarks, geographical features, structures (natural and manmade): the Nile; the Equator; the Rocky Mountains; the Burj Khalifa; the Great Barrier Reef
• Street and road names: Main Street; Cedar Drive; Notting Hill
• Nationalities, languages, races, tribes: American; British; Norwegian; Mexican; Hindi; Masai
• Days of the week, months of the year: Tuesday; Sunday; June; November
• Historical eras, named historical events, holidays: the Bronze Age; World War II; Valentine’s Day
• Special events: the Commonwealth Games; the Golden Globe Awards
• Planets: Jupiter; Venus
• Companies, organizations, institutions, brand names: Coca-Cola; Disney; the United Nations; the World Bank; Oxford University
• Religions, deities, holy books: Christianity; Islam; Vishnu; the Bible

Nouns that are notably not capitalized include academic subjects, professions, medical conditions, elements, plants, animals, and minerals.

However, we still capitalize the names and proper nouns that may appear within these, e.g. Alzheimer’s disease; German shepherd.

Also note that family names like ‘Dad’, ‘Grandma’, and ‘Uncle’ are only capitalized when addressing the person or referring to them by that name. In phrases like ‘my dad’, ‘his grandma’, and ‘their uncle’, where you are using the noun to describe the relationship rather than to name the person, the words are all lowercase.

Should you capitalize seasons?

The four seasons – spring, summer, fall/autumn, and winter – are common nouns and therefore do not need to be capitalized unless they are used at the beginning of a sentence or in a title.

Some people, mistakenly believing that the seasons are proper nouns, capitalize them mid-sentence.

Do cardinal directions need to be capitalized?

The directions found on a compass (north, south, east, and west) and their derivatives (northern, northeast, etc.) do not need to be capitalized when referring to a direction or general area. They often appear as part of a proper noun referring to a geographic region (the East Coast, South Sudan, Southeast Asia), in which case we apply the capitalization rules of proper nouns.

• Virginia is southeast of West Virginia.
• Indonesia is the southernmost country in Southeast Asia.
• The north of the city is more affluent than the south.

Check your style guide for further intricacies on this topic.

Should you capitalize the first word after a colon?

Rules for capitalization after colons vary depending on what is following the colon.

1) If the colon introduces a list or an incomplete sentence, do not capitalize the first word after the colon.

• Suzie needs some extra supplies for her art class tomorrow: origami paper, scissors, popsicle sticks, and glue.
• There is only one person in the world who could solve this problem: me.

The exception to this would be if the word is a proper noun or acronym that would usually be capitalized.

2) If the colon comes before a complete sentence, check your style guide.

APA style states that you should always capitalize the first word following the colon if it is part of a complete sentence.

• One thing is for sure: We won’t be going to the theme park if it is raining.

The Chicago Manual of Style, on the other hand, keeps the first word lowercase even if it is part of a complete sentence.

• One thing is for sure: we won’t be going to the theme park if it is raining.

However, if more than one complete sentence is introduced by the colon, we go back to using capital letters.

• Here’s the plan: If it’s sunny, we’ll go to the theme park. If it rains, we’ll hang out at the mall.

If you have a particular style guide to follow, check what it says regarding when to use capital letters after colons. If not, just pick one of these options and try to be consistent with it.

Capitalizing abbreviations (acronyms and initialisms)

Acronyms and initialisms are both types of abbreviation that shorten a phrase to a series of letters, usually representing the first letter of each word in the phrase. Common examples are NASA, WHO, FAQ, and VIP.

You can read more about abbreviations, acronyms, and initialisms here, but the main rule for writing them is this:

All letters in acronyms and initialisms should be capitalized to distinguish them from regular words.

Of course, this capitalization rule may not apply so strictly in casual settings like internet chat rooms, where that extra keystroke to create uppercase text would negate the convenience of writing things like ‘gg’, ‘brb’, and ‘ty’.

Additionally, there are some Latin abbreviations that follow different capitalization rules.

Which words are capitalized in a title?

There are different ways to approach title capitalization for articles, magazines, and blogs. The rules you follow will depend on the style guide you are using (if any), but the three main options are:

• Sentence case: Only acronyms, proper nouns, and the first word are capitalized in titles. Everything else is lowercase. Just like writing a normal sentence.
• Title case: The first and last words of a title are always capitalized, as well as any nouns, verbs, adjectives, adverbs, and pronouns. Other words are sometimes capitalized.
• Proper case: Capitalize the first letter of every word in the title, without exception.

Most style guides recommend either sentence case or title case capitalization.

However, there is some disagreement over whether certain types of words, like conjunctions and prepositions, should be capitalized in title case.

AP style capitalizes prepositions over three letters, for example, whereas Chicago style does not capitalize any prepositions in title case; even longer words like ‘underneath’.

All style guides agree that articles (a, an, the) are lowercase unless they appear as the first word in a title, in which case they are uppercase.

Titles of books, songs, films, plays, and other compositions generally use title case.

How to use capital letters in a quotation

You should capitalize the first word in a quotation if the entire quotation is a full sentence. If the quotation is a fragment, don’t capitalize the first word (unless it is a proper noun).

• The winner proclaimed that he was “overwhelmed with joy”, although his face did not show it.
• The winner proclaimed “This is a monumental day for our team and for our sport.”

Conclusion

We hope this guide has helped you understand what should be capitalized in a sentence, and what should not. When it comes to capitalization rules for English writing, some are quite easy to follow and others are more complicated.

If you have a preferred writing style guide, you can refer to that to check whether capitalization is required in any given context.

You may also find it helpful to use a writing assistant like Grammarly, which checks as you write and highlights any mistakes, including any errant capital letters. The tool will help you understand which words to capitalize and which to leave as lowercase.

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