Rules on the Correct Use of Punctuation Marks

Punctuation is used to create sense, clarity, and stress in sentences. You use punctuation marks to structure and organize your writing. You can quickly see why punctuation is important if you try and read this sentence which has no punctuation at all:

perhaps you dont always need to use commas periods colons etc to make sentences clear when i am in a hurry tired cold lazy or angry i sometimes leave out punctuation marks grammar is stupid i can write without it and dont need it my uncle Harry once said he was not very clever and i never understood a word he wrote to me i think ill learn some punctuation not too much enough to write to Uncle Harry he needs some help

Now let’s see if punctuating it makes a difference!

Perhaps you don’t always need to use commas, periods, colons etc. to make sentences clear. When I am in a hurry, tired, cold, lazy, or angry I sometimes leave out punctuation marks. “Grammar is stupid! I can write without it and don’t need it,” my uncle Harry once said. He was not very clever, and I never understood a word he wrote to me. I think I’ll learn some punctuation – not too much, enough to write to Uncle Harry. He needs some help!

Use the pages in this punctuation section to learn how to make your English clearer and better organized.

Period (.)

The period (known as a full stop in British English) is probably the simplest of the punctuation marks to use. You use it like a knife to cut the sentences to the required length. Generally, you can break up the sentences using the full stop at the end of logical and complete thought that looks and sounds right to you.


  • Rome is the capital of Italy.
  • I was born in Australia and now live in Indonesia.
  • The Dalai Lama is the spiritual leader of the Tibetan people.

Many abbreviations require a period. Dr, Mr, Mrs, and Ms do not take a period in British English, nor do most abbreviations taken from the first capital letters such as MA, Phd, or CIA. In American English, some of these do require periods or both usages are correct (with and without periods). If you require 100% accuracy in your punctuation, refer to a detailed style guide for the abbreviation usage rules in the variety of English you are using.


  • I will arrive between 6 a.m. and 7 a.m.
  • We are coming on Fri., Jan. 4.

Often you will see a sentence concluding with three dots. This indicates that only part of the sentence or text has been quoted or that it is being left up to the reader to complete the thought.


  • The Lord’s Prayer begins, “Our Father which art in Heaven…”
  • He is always late, but you know how I feel about that…

Sometimes a single word can form the sentence. In this case, you place a full stop after the word as you would in any other sentence. This is often the case when the subject is understood as in a greeting or a command.


  • “Goodbye.”
  • “Stop.”

Numbers use periods in English to separate the whole number from the decimal. A period used in a number is also called a “decimal point” and it is read “point” unless it refers to money.


  • $10.43 = ten dollars and 43 cents
  • 14.17 = fourteen point one seven

Comma (,)

There are some general rules which you can apply when using the comma. However, you will find that in English there are many other ways to use the comma to add to the meaning of a sentence or to emphasize an item, point, or meaning.

Although we are often taught that commas are used to help us add ‘breathing spaces’ to sentences they are, in fact, more accurately used to organize blocks of thought or logical groupings. Most people use commas to ensure that meaning is clear and, despite grammatical rules, will drop a comma if their meaning is retained without it.

When making a list, commas are the most common way to separate one list item from the next. The final two items in the list are usually separated by “and” or “or”, which should be preceded by a comma. Amongst editors, this final comma in a list is known as the “Oxford Comma”.


  • I met Harry, we went for a swim together, and afterward, Harry went home.
  • I like your son, I might even love him, but he is not a very good soccer player.


  • For dinner, I had soup, fish, chicken, dessert, and coffee.
  • This afternoon I went to Oxford Circus, Picadilly, Hamstead, and Gatwick Airport.

A list of adjectives usually requires commas. However, if an adjective is modifying another adjective you do not separate them with a comma (sentence 3).


  • She was young, beautiful, kind, and intelligent.
  • The house we visited was dark, dreary, and run-down.
  • She was wearing a bright red shirt.


  • Tony ran towards me, fell, yelled, and fainted.
  • The boy leaped, spun, twisted, and dove into the water.


  • The car smashed into the wall, flipped onto its roof, slid along the road, and finally stopped against a tree.
  • The dog leaped into the air, snatched the frisbee in its mouth, landed, and ran off into the forest.

Use a comma to enclose non-defining relative clauses and other non-essential details and comments. The comma is placed on either side of the insertion.


  • China, one of the most powerful nations on Earth, has a huge population.
  • Jason’s grandmother, who was born in 1930, lived through the Second World War.
  • Cats, unlike dogs, do not respect their masters.
  • My friend, Jim, likes to go scuba diving.


  • Hearing that her father was in the hospital, Jane left work immediately.
  • Walking to the bus stop that morning, Sam knew it was going to be a special day.


  • She lives in Paris, doesn’t she?
  • We haven’t met, have we?


  • Yes, I will stay a little longer, thank you.
  • No, he isn’t like other boys.
  • Wait, I didn’t mean to scare you.

Putting a comma in the wrong place can lead to a sentence with a completely different meaning, look at these two sentences:

  • I detest liars like you; I believe that honesty is the best policy. = I detest you because you are a liar.
  • I detest liars, like you; I believe that honesty is the best policy. = You and I both detest liars.

Exclamation Mark (!)

The exclamation mark is used to express exasperation, astonishment, or surprise, or to emphasize a comment or short, sharp phrase. In professional or everyday writing, exclamation marks are used sparingly if at all.


  • Help! Help!
  • That’s unbelievable!
  • Get out!
  • Look out!

You can also use exclamation marks to mark a phrase as humorousironic or sarcastic.


  • What a lovely day! (when it obviously is not a lovely day)
  • That was clever! (when someone has done something stupid)

In very informal writing styles (SMS, chat, Twitter or Facebook, etc.), an exclamation mark is sometimes combined with a question mark to indicate both surprise and slight uncertainty. Double and triple exclamation marks are common in very informal writing styles but are a sign of being uneducated in less casual correspondence.

Examples of Casual Writing:

  • He’s getting married!?
  • That’s insane!!!

Question Mark (?)

Use the question mark at the end of all direct questions.


  • What is your name?
  • Do you speak Italian?
  • You’re Spanish, aren’t you?

DO NOT use a question mark for reported questions.


  • He asked me what my name was.
  • She asked if I was Spanish.
  • Ask them where they are going.

Long questions still need question marks


  • Isn’t it true that global warming is responsible for more and more problems which are having a disastrous effect on the world’s climate and leading to many millions of people in countries that can least afford it having to contend with more and more hardship?
  • Why is it that even though you are unkind to me, ignore me when I ask you for help, and consistently forget to thank me when I do favors for you, you still claim to want me to be your friend and appear surprised when I prefer to hang out with other people?

Question marks can sometimes appear within sentences


  • There is cause for concern (isn’t there?) that the current world economic balance is so fragile that it may lead to a global economic downturn.
  • “Why is she here?” asked Henry.

Colon (:)

The colon expands on the sentence that precedes it, often introducing a list that demonstrates or elaborates whatever was previously stated.


  • There are many reasons for poorly written communication: lack of planning, poor grammar, misuse of punctuation marks, and insufficient vocabulary.
  • He collected a strange assortment of items: bird’s eggs, stamps, bottle tops, string, and buttons.
  • Peter had an eclectic taste in music: Latin, jazz, country and western, pop, blues, and classical.
  • He had just one fault: an enormous ego.

The colon is also used to divide the hour from the minutes in writing time in English.


  • 4:15 = “four fifteen”
  • 6:45 = “six forty-five”

Semicolon (;)

The semicolon is somewhere between a full stop and a comma. Semicolons can be used in English to join phrases and sentences that are thematically linked without having to use a conjunction (example 1 below). Semicolons can also be used instead of commas to separate the items in a list when the items themselves already contain commas (example 2 below).


  • I like your brother; he’s a good friend.
  • Many great leaders, Churchill, leader of Britain during the Second World War; Alexander, the great Emperor and general; and Napolean, the brilliant French general, had strong characters, which were useful when their countries were at war but which did not serve them well in times of peace.

Quotation Mark (“)

Use quotation marks to cite something someone said exactly. When rephrasing what someone told you, no quotation marks are needed.


  • “I’m going to the store now,” she said.
  • Harry told me, “Don’t forget your soccer jersey.”
  • Harry told me not to forget my soccer jersey.

If quoting others within a quote, both single and double quotation marks are used to set the two separate quotations off from each other.


  • ‘I haven’t spoken to Peter for months,’ Dianne said. ‘The last time I spoke to him he said, “I’m going to Bahrain and won’t be back for about three years”, I’ve heard nothing since then’.

You may see single or double quotation marks used to mark out idiomatic or unfamiliar expressions


  • I’ve always thought that he was very annoying, a bit of a ‘pain in the neck.’
  • I’m not sure what you mean by “custodial care”, but I’m sure you will explain it to me.

Quotation marks both single and double are also used for specific purposes in bibliographic references or when citing sources in academic writing. There are a number of ways of organizing bibliographies which set out standard formats. Most organizations and academic institutions will prefer one of these or have their own format published in a ‘style guide’.


  • “The Migration Flight of the Lesser Tweazle”, by Jeremey Adams, The Bird Spotter Magazine July 2009.

Apostrophe (‘)

The apostrophe probably causes more grief than all of the other punctuation marks put together! The problem nearly always seems to stem from not understanding that the apostrophe has two very different (and very important) uses in English: possession and contractions.

The most common use of apostrophes in English is for contractions, where a noun or pronoun and a verb combine. Remember that the apostrophe is often replacing a letter that has been dropped. It is placed where the missing letter would be in that case.

Using “notisn’t, hasn’t, hadn’t, didn’tis not, has not, had not, did not, would not
Using “isshe’s, there’s, he’s, it’s, Mary’sshe is, there is, he is, it is, Mary is, Jim is
Using “amI’mI am
Using “willI’ll, you’ll, she’ll, we’ll, they’llI will, you will, she will, we will, they will
Using “wouldI’d, you’d, he’d, we’d, they’dI would, you would, he would, we would, they would
Using “haveI’ve, you’ve, we’ve, they’veI have, you have, we have, they have
Using “areyou’re, they’re, we’reyou are, they are, we ar

People, even native English speakers, often mistake its and it’syou’re and yourwho’s and whose, and they’retheir and there. See below for the difference.


  • It’s a nice day outside. (contraction)
  • The cat is dirty. Its fur is matted. (possession)
  • You’re not supposed to be here. (contraction)
  • This is your book. (possession)
  • Who’s at the door? (contraction)
  • Whose shoes are these? (possession)
  • They’re not here yet. (contraction)
  • Their car is red. (possession)
  • His car is over there. (location)

In most cases, you simply need to add ‘s to a noun to show possession


  • a ship’s captain
  • a doctor’s patient
  • a car’s engine
  • Ibrahim’s coat
  • Mirianna’s book

Plural nouns that do not end in s also follow this rule:


  • the children’s room
  • the men’s work
  • the women’s club

Ordinary (or common) nouns that end in s, both singular and plural, show possession simply by adding an apostrophe after the s.


  • the bus’ wheel
  • the babies’ crying
  • the ladies’ tennis club
  • the teachers’ journal

Proper nouns (names of people, cities, countries) that end in scan form the possessive either by adding the apostrophe + s or simply adding the apostrophe. Today both forms are considered correct (Jones’s or Jones’), and many large organizations now drop the apostrophe completely (e.g. Barclays Bank, Missing Persons Bureau) when publishing their name.


  • The Hughes’ home (or the Hughes’s home)
  • Mr. Jones’s shop (or Mr. Jones’ shop)
  • Charles’ book (or Charles’s book)

Hyphen (-)

A hyphen joins two or more words together while a dash separates words into parenthetical statements. The two are sometimes confused because they look so similar, but their usage is different. Hyphens are not separated by spaces, while a dash has a space on either side.

Generally, hyphens are used to join two words or parts of words together while avoiding confusion or ambiguity. Consult your dictionary if you are not sure if a hyphen is required in a compound word, but remember that current usage may have shifted since your dictionary was published.


  • run-down
  • up-to-date

There are some cases where hyphens preserve written clarity such as where there are letter collisions, where a prefix is added, or in family relations. Many words that have been hyphenated in the past have since dropped the hyphen and become a single word (email, nowadays).


  • co-operate
  • bell-like
  • anti-nuclear
  • post-colonial
  • great-grandmother
  • son-in-law

In some cases though, a hyphen does change the meaning of a sentence.


  • I am thinking of re-covering my sofa (= to put a new cover on it)
  • I would like to recover my sofa. (= from someone who has borrowed or stolen it)

Hyphens in Numbers

Use a hyphen with compound numbers from twenty-one to ninety-nine.


  • fifty-one
  • eighty-nine
  • thirty-two
  • sixty-five

In written fractions place a hyphen between the numerator and denominator except if there is already a hyphen in either the numerator or the denominator.


  • two-fifths
  • one-third
  • three-tenths
  • nine-hundredths
  • sixty-nine eighty-ninths

Use a hyphen when a number forms part of an adjectival compound


  • France has a 35-hour working week.
  • He won the 100-meter sprint.
  • Charles Dickens was a great nineteenth-century novelist.

Dashes (–)

Dashes can be used to add parenthetical statements or comments in much the same way as you would use brackets. In formal writing, you should use the bracket rather than the dash as a dash is considered less formal. Dashes can be used to create emphasis in a sentence.


  • You may think she is a liar – she isn’t.
  • She might come to the party – you never know.

Brackets ( ) and Square Brackets [ ]

The difference between a ‘bracket’ and a ‘parentheses’ can be a bit confusing. Generally, ‘parentheses’ refers to round brackets ( ) and ‘brackets’ to square brackets [ ]. However, we are more and more used to hearing these referred to simply as ’round brackets’ or ‘square brackets’.

Usually, we use square brackets – [ ] – for special purposes such as in technical manuals. Round brackets – ( ) – are used in a similar way to commas when we want to add a further explanation, an afterthought, or comment that is to do with our main line of thought but distinct from it. Many grammarians feel that the parentheses can, in fact, be replaced by commas in nearly all cases.


  • The government’s education report (April 2005) shows that the level of literacy is rising in nearly all areas.
  • I visited Kathmandu (which was full of tourists) on my way to the Himalayas for a trekking expedition.
  • You can eat almost anything while traveling in Asia if you are careful to observe simple rules (avoiding unboiled or unbottled water is one of the main rules to be aware of).