Five places to use the full stop, or period, and when to omit it

The full stop, or period. When to use it, and when not to use it.

It’s surprising how much there is to say about a punctuation mark that most of us probably don’t normally give a second thought to. And while this post doesn’t promise to cover absolutely everything there is to know about the full stop - it does cover its most common uses.

The full stop

The full stop is the most commonly used punctuation mark in English.

Its main function, as we know, is to mark the end of a sentence which isn’t an exclamation or a question - as in the following two examples of the opening lines of novels:

“Mother died today.” (The Stranger by Albert Camus.)

“Into the face of the young man who sat on the terrace of the Hotel Magnifique at Cannes there had crept a look of furtive shame, the shifty, hangdog look which announces that an Englishman is about to talk French.” (The Luck of the Bodkins by PG Wodehouse.)

But the full stop is so much more than a simple mark at the end of a sentence.

Even in the two brief examples above we can see it's a key tool in the fiction writer’s toolbox. Each full stop is placed exactly where it’s needed to create the rhythm, pace, and dramatic effect the writers wanted.

So, how else do we use them?

When do we use the full stop?

For dramatic effect in informal writing

The full stop is used for emphasis or dramatic effect in informal writing such as text messages and social media updates, where a full stop between each word creates a pause and adds impact. For example:

  • Oh. My. God.
  • Worst. Movie. Ever.
  • Just. Do. It!

In abbreviations

Full stops are also sometimes used to show abbreviated words or phrases.

Latin abbreviations are very often written with them:

  • a.m. - ante meridiem/before midday
  • p.m. - post meridiem/after midday
  • e.g. - exempli gratia/for example
  • etc. - et cetera/and the rest
  • i.e. - id est/in other words

There are different recommendations for this use of full stops, and I've seen at least one university stating they're not necessary in Latin abbreviations.

Many universities also frown upon using Latin abbreviations at all in academic English (except perhaps in footnotes), preferring instead the use of 'for example' instead of 'e.g.', etc.

If you're writing academic English, always follow your individual university's guidelines.

In time abbreviations

a.m. (ante meridiem) and p.m. (post meridiem) are written in lower case with two full stops in British/UK English.

  • 10 a.m.
  • 5.30 p.m.

In North American and Australian English there are no full stops. But North American English favours no full stops and (small) capitals:

  • 10 AM
  • 5.30 PM

Whereas Australian English favours no full stops and lower case:

  • 10am
  • 5.30pm

Who knew that writing the time could be so complicated?

On Twitter

If you’re a Twitter user, you might already be familiar with this social media tip.

When you tweet someone directly, or reply to them using their Twitter handle, only the people you jointly follow will see that tweet in their feed.

But if you put a full stop before the @ symbol on your tweet, it’s potentially visible in the feeds of all your Twitter followers.

For example:

.@typely_com I love the typewriter sound on typely.com 😊 #proofreading #writing

When don’t we use the full stop?

For titles, headings and subheadings

Generally, a full stop is not used at the end of a title, heading or subheading.

However, if you use a heading at the beginning of a paragraph as part of the text, this would normally close with a full stop (or a colon). You can see and example of this in the heading examples directly below:

Social Media Marketing Platforms

Facebook. More than 1.2 million people use Facebook every…

Twitter. Businesses can use Twitter…

Acronyms

It used to be normal practice for some acronyms and initialisms to be written with full stops between the individual letters, but they’re now commonly written without punctuation. Here are some familiar examples:

  • BBC – British Broadcasting Corporation
  • CNN – Cable News Network
  • EFL – English as a Foreign Language
  • ESL – English as a Second Language
  • FBI – Federal Bureau of Investigation
  • NATO – North Atlantic Treaty Organization
  • UK – United Kingdom
  • UNICEF – United Nations Children’s Emergency Fund

Mr and Mrs

For titles such as Mrs, Mr, Ms, and Dr, British/UK English favours writing these without a full stop.

In American English the preference is to use a full stop:

  • Mrs.
  • Mr.
  • Ms.
  • Dr.

The full stop in text messaging and instant messaging

In the informal writing of texting and instant messaging, the full stop has fallen out of favour and it’s now normal to end a message with no punctuation, as if the conversation has not ended.

According to some linguists, ending a message with a full stop in this context can be interpreted as having some sort of significance other than simply indicating the end of a sentence – it means the conversation/discussion is over, or that the writer is angry or is being sarcastic.

I’m not sure what I think about this. I still use full stops at the end of texts, but only because it seems normal and ‘correct’ to me. Am I in a minority now? Maybe.

What I do see is that we’re using all forms of punctuation less and less, including the full stop, and I know this is all part of the natural evolution of language and language use. However, the full stop is such a useful punctuation mark, in many cases indispensable, and the humble . will be around for a long time yet.