When it comes to punctuation, periods are one of the most commonly used marks, so it comes in handy knowing how to use them. This article will teach you everything you need to know to use periods competently.
This guide is part of our free online Grammar Book.
So let's start with the basics: what exactly are periods in writing? That's an easy one: they're a form of punctuation.
The other main ones are:
That's quite a lot, isn't it? I bet it's more than you thought. But the only other two that can be used to end a sentence are the question mark and the exclamation mark. And of all these, the most used punctuation in English is the period. It's also known as the full stop in the U.K. and other British English-speaking countries.
Periods are placed at the end of a sentence to mark a pause. It's a much longer pause than you'd observe with a comma or other forms of punctuation.
Place your periods directly after the last word at the end of your sentences without a space in between. Do leave a space between the period and the first word of the following sentence (some even leave two spaces - it's a stylistic choice).
Do you want to know how and when to use periods? Great, because that's what you'll learn in this article. I will start by telling you when not to use periods because it's a much shorter list!
With periods being the most commonly used form of punctuation, it's much easier for me to tell you when not to use them. There are three significant instances in which you shouldn't use periods.
Questions - also known as interrogative sentences - are a way to elicit information from someone.
Here are a few examples:
Good morning, how are you?
How did he get here?
Should we grab Italian or Mexican?
Watch out for indirect questions, though - they will end with a period and not a question mark, but that's because an indirect question is actually a declarative sentence. More on that later.
Exclamations - also known as exclamatory sentences - allow you to express emotion within your sentence. Usually, this will be a pretty intense emotion like surprise, anger, or disgust rather than sadness or disappointment.
You got here so fast!
That's gross, Stefan!
You use an exclamation mark because this punctuation communicates emotion, whereas a full stop is relatively neutral. Look at the two following sentences, which are identical, but one has a period, and one has an exclamation mark. They communicate a completely different message, and how they would sound when you read them aloud is entirely different.
Oh, you're here.
Oh, you're here!
Depending on the context, the first sentence could indicate disappointment, sarcasm, or even complete neutrality. The second, however, shows excitement or surprise.
If you're citing a title or quote that ends with a question or exclamation mark, you won't use a period at the end of the sentence, even if it is a declarative sentence. That's because we never use two punctuation marks in succession. Think about it - that would look a little silly.
Here is an example to show you what I mean:
As soon as he saw me he yelled out, "Danny, I'm over here!"
The quoted sentence 'Danny, I'm over here!' is exclamatory, but the sentence it is contained in is a declarative one. It's just somebody reporting what somebody else has said. So technically, the sentence should end with a period. But since the quoted sentence is at the end of the main sentence and ends with an exclamation mark, to use a period would mean to use two punctuation marks in succession. So instead, we use the exclamation mark and leave the period.
Here's another example, this time using a movie title and a question mark:
The group voted and we all watched Dude, Where's My Car?
Even though the sentence above isn't a question, the fact the movie title ends with a question mark and is at the end of the sentence means the sentence ends with a question mark despite being a declarative sentence.
If you want to avoid ambiguity, you can always move the citation so it's not at the end of the sentence. Here's one way you could do that with the previous example:
The group voted and we all watched Dude, Where's My Car? on the big screen.
Alright! Now we've covered when not to use periods, let's talk about when you should use periods. In this section, you'll see that periods are pretty versatile: they can be used to end a sentence, which is how most people know them, but that's not all they can do.
We'll start with the two types of sentences you can and should use periods with.
Declarative sentences are also known as assertive sentences, and their purpose is to state a general truth or an opinion, give information or make requests in a non-forceful way. The lack of an exclamation mark gives it a calm energy and shows you are simply making a statement. Use a period to end these types of sentences.
Here are some examples:
It's nice to meet you, my name's Carly.
I'll be there in one hour.
Sorry to hear that you lost your job.
Don't forget: indirect questions are a type of declarative sentence, too. They're just a way of telling someone about a question someone else asked. Here's an example of an actual question (interrogative sentence) and an indirect question (declarative sentence).
What is the square root of four?
The teacher asked us what the square root of four was.
Notice how the former ends with a question mark and the latter ends with a period.
Imperative sentences allow you to give commands. They can sometimes end with an exclamation mark, but often a period will suffice.
Here are some examples:
Please, take a seat.
Sally, be a darling and pass me the salt.
Don't go in there.
As I mentioned earlier, periods are not only used as a way to end sentences; they also have a few other functions. And one of those is to help us form abbreviations. What's an abbreviation, you ask?
Here are some common abbreviations:
Usually, the period comes after the letters if each letter stands for a word, and it comes after the word if the abbreviation only shortens a single word.
Note that depending on your preferred style guide and the country you live in, you might not need to use periods with all abbreviations. I'm sure you see 'USA' without periods just as often as you've seen 'U.S.A.' with periods. So it's really up to you to decide... or refer to your chosen style guide.
Another form of abbreviation is initials. If you only know the first letter of someone's first name (and sometimes middle name), or you only want to disclose the first letter of your own name, then you can do that and follow each letter with a period. Here are some examples of famous people who do that:
If a sentence ends with an abbreviation period, you shouldn't add another period, even if it's a declarative or imperative sentence. You can, however, add a different punctuation mark.
I'm going to need your R.S.V.P.. ❌
I'm going to need your R.S.V.P. ✅
I'm going to need your R.S.V.P., but it can wait until tomorrow. ✅
Ellipsis, while not exactly a period, comprises three periods, so I thought it deserved mention here, especially since it can sometimes replace a period.
The role of an ellipsis is to either add suspense, show a thought trailing off, or show that words have been removed from a quote. If an ellipsis is at the end of the sentence, you don't need to add another full stop afterward, even if it's a declarative or imperative sentence.
I was sure I'd locked the door...
You look surprised to see me...
Now where did I put my...
Periods are also used in other contexts outside of grammar. For example, to get to this article, you had to head to a website address that contained a period. Although in this context, it would be called a 'dot.'
Www [dot] writing tips [dot] org
You'll also find this period in file names to separate the file name from the file extension.
And I'm sure you'll find it used in many more ways within the computing and programming world.
Another place you'll often see a period is in mathematics. For instance, to separate the decimals from the whole number:
While some use a comma for this, a period is also perfectly acceptable. It's also sometimes used as an alternative for the multiplication sign, although you'll find it placed in the vertical middle of the line:
2 ⋅ 2 = 4
We've covered most of what you need to know regarding when and when not to use periods. There are just a couple of special cases I want to go over with you.
Quotation marks are used when you quote what somebody else has said, cite works, or draw attention to a word.
I mentioned in the first section that you should place your periods at the very end of the sentence, after the final word. But there's one case where there'll be one thing separating the last word from the period, and that's when using single or double quotation marks. Look at the following example:
He responded, "It takes two to tango."
In this example of reported direct speech, the narrator is telling us what somebody else said by quoting it directly, so it requires quotation marks. Notice that the sentence's closing period comes before the closing quotation marks. This is definitely stylistic and is less commonly seen in the U.K., for example, where they tend to place the period after the quotation marks.
Here are some more examples:
The book described her as 'tall' and 'intimidating.'
I love his poem "The Raven."
Parentheses - also known as brackets - are a way to add nonessential information to a sentence while keeping it separate and making it clear the info's nonessential.
Though they're convenient, you should know a few things about using periods with them.
Don't use a period when the part in brackets isn't a complete sentence.
When I arrived at the station (much earlier than planned), I headed to the ticket office.
When the part in brackets is a complete sentence, use a period.
I arrived at the station. (I got there much earlier than planned.) I headed to the ticket office.
Notice how the period is placed inside the brackets because the sentence is complete.
That concludes this article on periods. I hope you found it helpful and feel you have a good command over when and how to use a period.
Let's summarize what we've learned:
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