Capital ideas

The rules of capitalization in English can feel confusing. We all understand that sentences should begin a with a capital letter, and most of use remember that proper nouns (e.g. Satyadarshin, Bristol, Clifton Suspension Bridge) should be capitalized. Beyond that, people generally seem to get a bit hazy on what the principles are, so here are a few solid rules of thumb.

The biggest mistake

The most common error I see is the tendency to capitalize words that are important to the author, often at the expense of recognized proper nouns. The idea seems to be that a capitalized word feels more significant, so authors end up “demoting” nouns that feel less compelling.

Unfortunately that’s not how written English works: it actually has fairly solid conventions about capitalization. Whilst it might feel tempting to break those conventions, most of the time your reader can’t be expected to understand your intentions: you may just end up looking careless, and that impression may well spill over into their perception of your ideas, brand, product, or event.

Conventions can and do change over time: it’s disputed whether we should now use “internet” over “Internet” for example. We’re now accustomed to writing iPhone, iPad, and so forth; most of us are now (sadly) at least familiar with the acronym mRNA. (These are four examples of camelCase, which until the late 200’s was mainly used in science and programming notation.) At the other extremes, in some contexts it’s acceptable to write in all caps, or even all lowercase.

The basic rules

In this article I’m going to summarize the basic conventions on capitalization. Remember that when you come across what looks like an exception, Google is your friend.

Names that are “proper nouns” and include cities, countries, languages, companies, religions, political parties, and festivals: so always Bristol, England, French, Buddhism, Apple, the Green Party or Greens, and Easter.

It gets tricky when words are used as a form of address, like Doctor or Nurse, when talking to or about someone specifically. It helps to think of the noun as being a substitute for their given name: if you could replace “Doctor” with “Jodie” and the sentence would still sound right, then probably you need to capitalize. By the same token, we talk about the Web (note the capital) as shorthand for the World Wide Web, not the web. If you really want to put your head in spin: we capitalize Earth when talking about it as a proper noun planet in relation to other stellar objects, but not as the body on which we live. So the Earth orbits the Sun in 356 days, but earth rotates on it’s own axis. Similarly, the sun we see in the sky is the same Sun we orbit.

Convention has it that we capitalize days and months but not seasons: so Monday and April, but spring and autumn. Similarly, time periods and events, but not centuries: so the Paleolithic, the Middle Ages, the Hundred Years War, but twentieth century.

Start a quote with a capital if it’s a complete sentence within your sentence for example, “If there’s anything more important than my ego around, I want it caught and shot now”. You don’t need to capitalize after colons or dashes because they don’t start a sentence.


  • Brand names
    YouTube, Mercedes-Benz, but note: iPhone
  • Companies, organizations, and institutions
  • Days of the week and months of the year (but not the seasons)
  • Historical episodes and eras (but not centuries)
  • Engineered structures
    Westminster Palace, the Blackpool Tower, the Titanic
  • Countries, territories, and cities
    England, the West Country, Devon, Exeter
  • Landmarks, natural and engineered
    Mount Olympus, Offa’s Dyke
  • Nicknames and epithets
    Stan “The Man” Lee; The Rock, Alfred the Great
  • Races, nationalities, and tribes
    Eskimo, Navajo, East Indian, Caucasian, African American
  • Religions and deities
  • Special occasions, holidays, and festivals
    The Olympic Games, Easter, the Cannes Film Festival
  • Streets and roads

Capitalizing all or nothing

It is in some situations appropriate to use all caps or all lowercase. It should be used cautiously, because it can easily reduce readability. This is usually a choice for main headings (i.e. titles and subtitles), pull quotes, and some forms of alert or notification, where extreme contrast is required. It is often best suited to purely graphic products like posters, book covers, and other typographic works.

Style guides

If you do a lot of writing or editing, I recommend keeping a copy of either the Oxford Style Manual, or the Chicago Manual of Style to hand.