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When to Use Periods (Grammar, Examples, Complete Guide)

Here’s when to use periods. An example sentence is as follow, “I am going to Paris tomorrow morning on official work if I finish it by evening I will return tomorrow night if not I will be back the next day”

The sentence above seems odd because it is missing punctuation marks. The correct use of punctuation will split the sentence into three meaningful sentences like this:

“I am going to Paris tomorrow morning on official work. If I finish it by evening, I will return tomorrow night. If not, I will be back the next day.”

Learn how and when to use the period in this short American English grammar guide.

What is a period?

A period is a punctuation mark that ends a sentence. It is a dot or a point we place at the bottom, after the last word, when we wish to end the sentence (like this dot). In English, we use periods at the end of a declarative sentence, and when we use abbreviations. Periods are also called full stops in UK English.

What is punctuation?

Punctuation refers to any mark, or character that we use, to make our writing clearer and easier to read.

When to use a period
When to use a period

Declarative sentences

Some examples of a period at the end of a sentence are:

  • My name is Jack.
  • I finished my homework quickly today. My mother said I could go outside and play.

Grammar rules when using a period

The word that follows a period begins with a capitalized letter. There are some exceptions to this rule, like certain brands such as iPhone, eBay.

It is common practice to start the following sentence with a single space after the period. Earlier, people used to use two spaces between sentences.

We can also use periods at the end of an indirect question. Some people also use it at the end of a polite request:

  • He asked me if he could use the towel.
  • Will you please help me with my homework.

How to use periods

Often, people get confused when quotation marks are involved in the sentence, and many of them tend to place periods in the wrong place.

When the quotes are at the end of a sentence, the period comes within the quotes.

  • Maria murmured to herself, “I will get through these tough times.”

When parentheses are used, a period should come within the parenthesis if there is a complete sentence within the parentheses.

  • I completed my tasks for the day. (They were all light ones.)
  • A period comes outside the parenthesis when the information inside the parenthesis is an extension of the sentence (like this period).


There are some differences when it comes to using periods between American and UK English.

Many standard abbreviations end with periods:

  • Doctor as Dr., and Mister as Mr., in American English.
  • Street as St.
  • Colonel as Col.
  • H. G. Wells.
  • The U.S.A. is also often written as USA or US.
Mr.B.A.e.g.A.M. or a.m.ft.
Mrs.M.A.i.e.P.M. or p.m.oz.

On the other hand, we do not use periods with:

  • Doctor as Dr, Mister as Mr, Junior as Jr in UK English.
  • Numerical abbreviations like 1st, 2nd, 14th,
  • Units of measures like miles per gallon as mpg, revolutions per minute as rpm, and kilogram as kg.
  • An exception to this is when using inches as in., where a period is commonly used.
  • Acronyms like NASA, FBI, NATO, and for abbreviations that consist of capitals like BBC, AD, and BC.
  • Chemical symbols like Na, Fe, H.

Lowercase abbreviations are usually written with periods:

  • i.e., e.g.

Academic degrees are written with or without periods:

  • BA, or M.S.

When a sentence ends with an abbreviation, it is not necessary to add an extra dot:

  • The most powerful country in the world is the U.S.A.

Abbreviated names that replace words:


More punctuation marks (all 26 marks)

.PeriodI got this at the fair.
?Question markHow many trucks does he have?
!Exclamation pointWow! You’re a great rider.
,CommaI like the movie, but the color grading is odd to me.
:ColonHere are some fun ideas for the party: trivia questions, shuffle board, and more.
;SemicolonI’ll visit you once I’m done with work; that’s a promise.
HyphenI have double-life situations.
En dashHow long is a China-Russia fight?
Em dashThe dog—and I’m afraid of four-legged animals—was so adorable.
( )ParenthesesHis favorite team (Chicago Bulls) has a chance to win the title. 
[ ]Square bracketsThe AP writer said “[head] of baseball operations was disappointed.” 
{ }Curly bracketsThe colors {orange, green, lilac, blue} are for the garage.
< >Angle brackets 
“ ”Quotation marksBryan called it a “great situation.”
ApostropheSome of Susan’s clothes are missing.
/Slash or VirguleI’m ordering food/dessert/more.
… EllipsesAccording to the school the “president… was disappointed.”
*Asterisk*Data from The Economist
&AmpersandTiffany & Co.
 •Bullet point• Simple
• Great
• Awesome
#Pound symbol#1 selling
~TildeBryan owns ~10 pairs of shoes.
@At symbol[email protected]
^Caret symbol3^3 = 27
|Pipe symbol 


  • Use a period/full stop at the end of a complete statement.
  • Remember the rules and common differences for periods between US and UK English when used in abbreviations.

Common questions

When should I use the period?

Use a period for both declarative and imperative sentences. A declarative sentence makes a statement. When an imperative sentence issues a request or command.

What are the grammar rules that govern the period?

Rule 1. Use a period at the end of a complete sentence that is a statement.

Rule 2. If the last item in the sentence is an abbreviation that ends in a period, do not follow it with another period.

Rule 3. Question marks and exclamation points replace and eliminate periods at the end of a sentence.


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About the author

Dalia Y.: Dalia is an English Major and linguistics expert with an additional degree in Psychology. Dalia has featured articles on Forbes, Inc, Fast Company, Grammarly, and many more. She covers English, ESL, and all things grammar on GrammarBrain.

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