How To Use Punctuation In Writing?

The most important purpose of accurate punctuation is to clarify sentences and avoid misunderstandings. This is a vast topic, and depending on who you are writing for, it may be worth investing in a style guide to cover all the potential considerations for punctuation, including regional variations.

In the US, The Chicago Manual of Style (University of Chicago, 2017) is a good starting point, while in the UK, with some different conventions, New Hart’s Rules: The Oxford Style Guide (Waddingham, 2014) is one of the most popular guides. 

Be aware that publications, organisations, and individuals may put a heavy emphasis on specific punctuation conventions that are not taught as definitive rules. For example, academic journals are often particular about the position of commas and periods in references, though one journal’s style may differ from another’s.


Apostrophes usually demonstrate either possession or abbreviations.

Apostrophes Demonstrating Possession

Possessive apostrophes are added with an s to most nouns. There are various rules for whether or not to add the extra s to words already ending in s, which can depend on style or personal preference. A good test is to try and pronounce the word. If it isn’t easy to say with an extra s, don’t add one:

  • Luke → Luke’s
  • the computer → the computer’s
  • Jess → Jess’s
  • the huntresses → the huntresses’

Possessive apostrophes indicate possession of the following noun or phrase:

  • The government’s problem.
  • The huntresses’ bows.

They are often used when discussing time:

  • in ten years’ time
  • in a decade’s time

The possessive apostrophe is not added to possessive pronouns: my, yours, his, hers, its, ours, theirs.

Apostrophes Demonstrating Abbreviation

Abbreviating apostrophes are used to replace missing letters. These are often used for combining to be or to have with a noun or pronoun, or to combine not with a verb.

  • I am fed up with this. → I’m fed up with this.
  • He is funny. → He’s funny.
  • She would have eaten that. → She would’ve eaten that.
  • It was not a good idea. → It wasn’t a good idea.
  • They could not start the car. → They couldn’t start the car.

Contractions are considered informal, so be wary of using them in written English. Most formal writing does not use contractions, though they may be acceptable in informal correspondence and written dialogue.

Abbreviating apostrophes are also used to shorten words for simpler or colloquial use:

  • the 1970s → the ’70s
  • Vietnam → ’Nam (colloquially used in the context of the war)

Apostrophes are also commonly used with plurals. This is often a punctuation mistake, such as adding an apostrophe when adding a plural s (I’m selling banana’s!). In some cases, however, this is done to avoid confusion, particularly when dealing with single letters or words that are not commonly used as nouns:

  • Mind your p’s and q’s.

The common expression in this example refers to letters, which are not typically recognised as nouns. It would be less clear without apostrophes: mind your ps and qs.

Using apostrophes with plurals in this way may be acceptable or not depending on the situation and you may be advised for or against their use by particular style guides. If in doubt, it may be best to rewrite your sentence, or consider using other punctuation or formatting to demonstrate an uncommon word or phrase:

  • After five failed weddings, she had said a lot of I do’s.
  • After five failed weddings, she had said a lot of “I do”s.
  • After five failed weddings, she had said a lot of I dos.
  • After five failed weddings, she had said “I do” a lot.


Commas separate different parts of a sentence. Their main function is to make sentences clearer, by grouping words, phrases, and clauses. They can separate clauses, separate direct speech, mark off parts of a sentence (like parentheses), and separate adverbial phrases.

Commas may sometimes be used flexibly, depending on the sentence (though remember they are there to add clarity), and deviations from typical conventions can be distracting and confusing. A good question to ask when considering if a comma is necessary or not is: is it easier to read the sentence with or without a comma? The option less likely to confuse or interrupt your reader is best, which is true of most writing rules.

Separating Clauses

Commas separate clauses in complex sentences, when we have a main clause and one or more subordinate clauses:

  • The passengers waited outside, while the steward refused to open the door.

The comma comes at the end of the first clause. In regular sentence structure, the comma often comes before a conjunction or other linking word. When complex sentences are reversed, with the linking word at the start of the sentence, the comma comes at the end of the first clause.

  • While the steward refused to open the door, the passengers waited outside.

Commas in complex sentences are sometimes seen as optional, as the comma often has little impact on the meaning or understanding of the sentence. This can depend on the sentence itself, as commas between clauses are less necessary in shorter sentences or sentences where the clauses are more directly connected:

  • They ate the cake before she could stop them.

With longer sentences, and sentences where the co-ordinating conjunction might create confusion with another noun, a comma can have a big impact on the meaning. This is particularly true with conjunctions like as and while, which could be interpreted as either for the purposes of or at the same time as:

  • The accountant demanded a new lamp, as the dim light made work impossible. (because working was impossible)
  • The accountant demanded a new lamp as the dim light made work impossible. (The demand was made at the same time as the light worsened.)

Commas are essential with particular types of subordinate clauses, such as non-defining relative clauses. Relative clauses, separated by the words who, whom, that, and which, may include defining information (with no commas) or additional information (with the clause separated by commas).

  • The man who had stolen the mango was imprisoned.
  • The man, who had stolen the mango, was imprisoned.

In the above example, the first sentence tells us this particular man (the one responsible for the crime, not someone else) was imprisoned. 

The second sentence tells us a man was imprisoned who happened to commit this crime. In the first sentence, the relative clause (who had stolen the mango) is used as an identifying cause of imprisonment; in the second sentence, it is additional information, not necessarily the cause of imprisonment (the clause may be confirming that he was guilty, for example). This is a subtle example. 

How much difference the commas make with relative clauses may vary depending on the situation:

  • The team who wanted the prize most won. (They won because of their passion.)
  • The team, who wanted the prize most, won. (They won and also had the most passion.)
  • Visitors that require special assistance should contact the front desk. (only those who require assistance should contact the desk)
  • Visitors, who require special assistance, should contact the front desk. (suggesting all visitors require special assistance)

This use of commas overlaps with considerations for separating additional information within a sentence.

Lists and the Serial Comma

Commas are used to separate items in lists of three or more words. This can apply to lists of different kinds of words, including lists of nouns, verbs, adjectives, and adverbs.

  • We ate cheese, ham, and tomatoes. (nouns)
  • On Saturday, Doris read, swam, and rested. (verbs)
  • They bought a new, tall, glass door. (adjectives)
  • Slowly, carefully, and deliberately, she opened the metal box. (adverbs)

Lists may or may not have a comma placed before the coordinating conjunction (and). This is called the serial comma, the Oxford comma or Harvard comma. Some English speakers argue that it is necessary while others believe it should be omitted. The truth lies somewhere in between:

  • A Full English breakfast consists of eggs, beans, sausages, and bacon. (serial comma)
  • A Full English breakfast consists of eggs, beans, sausages and bacon. (no serial comma)

In the above example, adding or removing the comma is unlikely to make any difference to how the sentence is understood. In can be argued, however, that in different contexts it may add or remove clarity. In the following sentences, the comma makes it clear how many items are in the list:

  • We ate ham, tomatoes, and eggs. (Comma separates three different food types.)
  • We ate ham, tomatoes and eggs. (No comma leaves the possibility that the three foods were combined.)
  • Dedicated to my co-workers, Paul and Jim. (No comma suggests Paul and Jim are the co-workers.)
  • Dedicated to my co-workers, Paul, and Jim. (Comma suggests Paul and Jim are thanked in addition to the co-workers.)

The serial comma can cause confusion, however, when it makes an item in a list appear to be additional information:

  • The group included a doctor, Jim Smith, and a baker. (suggesting the doctor is called Jim Smith)
  • The group included a doctor, Jim Smith and a baker. (suggesting Jim Smith is a third member of the group)

The particular cases for using the serial comma can depend entirely on the sentence: as these examples illustrate, it can sometimes remove ambiguity and can sometimes cause ambiguity. 

Generally, the serial comma is encouraged by the majority of American style guides and some British style guides. In-house guides or publications may either encourage or discourage it, so it is worth knowing what is acceptable for your particular piece of writing. 

However, this is a rare case where consistency is not always the best policy. The demands of a particular list may make the serial comma more or less useful.

In cases where the meaning appears to change with or without the comma, and neither is fully clear, it may be best to reword the sentence. In the examples below, neither option is clear:

  • Mary travelled to New York with Jim Smith, a doctor and a scholar. (Is Jim Smith both a doctor and a scholar, or did Mary travel with three people?)
  • Mary travelled to New York with Jim Smith, a doctor, and a scholar. (Is Jim Smith a doctor or did Mary travel with three people?)

Depending on which meaning is true, the list could be reworded, perhaps with a relative clause or additional conjunction, or by re-ordering:

  • Mary travelled to New York with Jim Smith and a doctor and a scholar.
  • Mary travelled to New York with a scholar and Jim Smith, who was a doctor.
  • Mary travelled to New York with a doctor, a scholar, and Jim Smith. (with or without the serial comma)

Direct Speech

Commas are used to separate narration from direct speech. A comma is used at the end of a quotation (inside the quotation marks) when describing narration follows the dialogue:

  • “They will be here by five,” said the secretary.

A comma may also be used at the end of a clause introducing a quote:

  • The secretary said, “They will be here by five.”

Narrative clauses may also be separated from direct speech with a comma when an action directly describes the quote, with verbs such as to say, to ask, and to reply:

  • He handed her the envelope, saying, “Here’s your letter.”

The comma is not used when we use another form of punctuation to end the quotation, such as an exclamation mark or question mark:

  • “Run!” she yelled.
  • “Are you sure you know the way out?” the princess asked.

A full stop is used if the narrative text either side of the quote is not directly connected to the quote:

  • “There’s nowhere left to go.” Resigned to his fate, Jim sat down.
  • Jim was mad as he spoke into the phone. “Where are my eggs?”

Direct speech may be broken around narrative text. If the quotation is a continuing sentence divided by narrative, the narrative text may end with another comma. If the continuing quotation starts a new sentence, a full stop should be used:

  • “Let’s get you out of those wet clothes,” she said, “and into something clean.” (The quote is one continuing sentence.)
  • “I’m not coming,” he told her. “Nothing you can say will persuade me.” (The quote contains two separate sentences.)

Separating Information

Additional information may be added to sentences separated by what can be called parenthetical commas. These behave the same way as parentheses. 

The information between two commas may be considered additional, and removing it should not affect the meaning of the sentence. Such information can be added for extra detail or commentary, and can come in the form of a few extra words or entire phrases or clauses:

  • The dress was unsuitable.
  • The dress, old and smelly, was unsuitable.
  • The dress, would you believe, was unsuitable.
  • The dress, old and smelly through years of use and no particular care for its upkeep, was unsuitable.

Parenthetical commas may also be used to move information from elsewhere in the sentence:

  • Kylie prepared to watch the fireworks with great excitement.
  • Kylie, with great excitement, prepared to watch the fireworks.
  • Kylie prepared, with great excitement, to watch the fireworks.

If you don’t put commas around such information, the sentence can become confusing:

  • The dress of course was unsuitable. (This makes the dress appear to belong to course, which does not work.)
  • Kylie with great excitement prepared to watch the fireworks. (This makes the excitement sound like part of Kylie’s name.)


Commas often follow adverbs or adverbial phrases used at the start of a sentence. This is done in the same way as using a comma to separate a subordinate clause at the start of a sentence. These adverbials frame the sentence with information that would typically come later (such as time, manner, or a comment), placing information before the main clause:

  • In time, we learnt the truth.
  • Quick as a flash, she threw the flaming pan into the sink.
  • Actually, there are no correct answers.

The comma comes directly after the adverb or complete adverbial phrase.

The adverb however is a well-known example of this, and is often taught as always being followed by a comma when placed at the start of a clause:

  • However, the deal was not accepted.

This is only true when however is used to mean on the other hand / in contrast (as a linking adverb). But however may also be used to mean by whatever means, which does not use a comma. In the following example, however is part of an adverbial phrase, so the comma comes at the end of the phrase, not directly after the adverb:

  • However much you want it, you cannot have my cake.

Ending Sentences

Most sentences end with a full stop, or period (.). This tells us the sentence is complete. Other options include exclamation marks (!) and question marks (?).

Exclamation marks can be used to add emphasis; demonstrating surprise, anger, and other emotions. They are particularly useful for exclamations in dialogue and for sharing surprising or alarming news.

  • Oh my! (exclamation)
  • “You’re not coming with me!” (dialogue)
  • The butcher has escaped – lock up your pigs! (alarming news)
  • Sofa for sale – now 50% off! (exciting news)

Exclamation marks can be associated with lazy writing, when they are used instead of more effective language. However, they can alter the tone of a sentence when used correctly. In the example below, an exclamation mark sets a different tone:

  • I won the prize, I’m so happy.
  • I won the prize, I’m so happy!

Question marks are used at the end of sentences that ask questions. They can be added to grammatically formed questions (i.e. with inverted question form) or to statements presented as questions (tag questions):

  • Where are the nuclear detonators? (standard present simple question form)
  • I told you that? (tag question)

Tag questions are common in spoken English, and are useful when writing dialogue and informal correspondence, but for most contexts it is more appropriate to use the correct question form in writing:

  • I told you that? → Did I tell you that?

Questions can also be ended with a full stop for rhetorical questions, where an answer is not expected. This helps demonstrate attitudes in writing:

  • I packed another box pull of pens. This tiresome job never seemed to end. Where did my life go wrong.

An exclamation mark can be used for questions in situations where a dramatic emotion is more important than the question being asked; for example, when a question is expressed forcefully. This implies that the question is not being asked for an answer, but as an expression of emotion:

  • “What have you done!”

Dramatic questions are sometimes punctuated with both a question mark and an exclamation mark. This is a matter of style and may not be considered acceptable in certain contexts, but a common technique is to combine the two punctuation marks in either order (?! or !?):

  • “Where are you taking me?!”

In some situations, sentences are left open, for example when we use a colon (:) to open a list or a comma (,) to open a letter with salutations.


The semi-colon (;) is rather nuanced in use and as such not always properly understood or used, even by native speakers. It has practically the same effect as a conjunction, without adding a word. It is typically used to connect two related main clauses which would otherwise form two separate sentences (i.e. neither clause should be dependent or include connecting words):

  • The kittens escaped; there was chaos in the shopping centre.
  • I am so happy we hired her; the last cook was awful.

Semi-colons are useful for bringing clauses closer together, which can vary your flow and draw direct attention to a consequence:

  • Fifteen per cent of employees were late last week; dismissals are to be announced shortly.

The above example could work as two sentences, but the semi-colon draws the dramatic second sentence closely to the cause. If you used a conjunction like so or therefore, the sentence would sound more reasoned (and reasonable) and lose some of the impact.

Semi-colons can also be used in lists, to separate items that already contain commas or to separate longer items (particularly if your list includes entire clauses):

  • The following groups of people were given priority boarding: those who had booked two months in advance; those who booked the VIP package; families with young children; the elderly and the infirm.


Quotes are usually demonstrated in English with quotation marks (“”) around words, phrases, or sentences. There are various conventions for demonstrating quotations, however, depending on the style used. Apostrophes may be used instead of quotation marks, ‘like this’, and italics may be used when highlighting foreign or unfamiliar words. Quotes may also be shown separated from the text, in block quotes:

  • Block quotes might look like this. They may be formatted with various different styles to the main text.

Punctuation belonging to a quotation typically belongs inside quotation marks, while punctuation belonging to the surrounding sentence belongs outside the quotation marks. However, in American English, if the quotation ends a sentence the punctuation should be included in the quotation marks, whether it is a complete sentence or not. Here are a few examples:

  • “This is an example of a complete sentence being quoted.” It ends with a full stop.
  • “This is an example of a complete sentence being quoted and framed by a narrative action,” said the teacher. “It is connected to the framing sentence with a comma.”
  • A sentence quoting “only a few words or phrases” might look this, with no additional punctuation belonging to the quote.
  • A British sentence ending in a quote of a few words or a phrase would look “like this”. (UK, full stop placed after closing quotation mark)
  • An American sentence ending in a quote of a few words or a phrase would look “like this.” (US, period placed before closing quotation mark)

There are many additional ways of showing quotations. Pay attention to how other writers present their quotes, particularly if you are writing for a specific organisation or publication. Be aware, also, that some writers go against convention in ways that are difficult to imitate. 

The acclaimed American novelist Cormac McCarthy, for example, does not use quotation marks at all (requiring a great deal of skill to indicate speech). Such exceptions require a mastery of the skill which may not always be clear for readers; other exceptions may, in fact, prove ineffective. The conventional methods are the most common because they work.

Capital Letters

In most texts, capital letters (letters in upper case) are used for the first letter of a sentence, for the first letter of a proper noun (or each important word of a proper noun phrase), for the pronoun “I” (and to spell out specific letters), and for certain acronyms and abbreviations:

  • This sentence starts with a capital T and goes on to spell out a specific letter.
  • The name and title of a Prime Minister (like Winston Churchill) start with capitals.
  • Abbreviations such as IBM and GMC are written in capitals.

Pay particular attention to using capitals with proper nouns. You may cause confusion with inconsistent capitals when capitalised and non-capitalised nouns can refer to two different things. For example, some buildings, such as pubs, may be named after animals, which would look strange if not properly capitalised:

  • Jim and Wendy met in the dog and duck. (animals?)
  • Jim and Wendy met in the Dog and Duck. (more clearly a building)

Capital letter use can depend on style. Key areas to look out for are place names, the names of institutions and organisations, dates, times, and compass directions. With all of these, a good general rule is that capitals are used when the noun specifically identifies the object, but not when the noun refers to the object as one of many possibilities:

  • I studied at Nottingham University. (“University” used as part of the name)
  • My university was in Nottingham. (“university” not used as part of the name)
  • The River Nile is 4,160 miles long. (“River” used as part of the name)
  • The Nile is a very long river. (“river” not used as part of the name)
  • The West imposed sanctions on the East. (“West” and “East” refer to identifiable political regions)
  • We travelled west for two weeks. (“west” refers to a general direction)

Capitals may be used more flexibly when a noun is used in an abstract or very specific situation, to highlight a particular convention or idea. This may highlight the difference between referring to an institution, e.g. the Catholic Church, or a location, e.g. the Catholic church. It may also highlight an importantly labelled object, for example:

  • If you wish to apply for a Residence Visa, fill in the application.

As a general noun, “residence visa” does not need to be capitalised, but in the context of specific instructions relating to a specific visa process, it may be. Such use should be applied carefully and clearly. If you wish to highlight a particular object with capitals, it must be treated as a proper noun consistently.

Titles and other important sentences can be written in Title Case. Typically, titles only capitalise the first letter of the first word and all the important words. What is considered an important word varies, but it usually means leaving only articles, prepositions, and conjunctions in lower case. Longer prepositions and conjunctions (i.e. those with more than one syllable) may also appear in upper case:

  • The President Shocks the World by Snoring Throughout Speech (“Throughout” remains capitalised as it is a longer preposition.)

Sometimes, the first letter of every word in a title is capitalised (full title case), and sometimes only the first letter is capitalised, as with sentence case (more common for captions or subheadings).

As variations in Title Case may indicate, to be consistent and accurate with capitals it is important to refer to a style guide relevant to your context. Style guides should lay out conventions for all capital letter use and exceptions, and if you find a situation that a style guide does not cover then you may be able to logically compare it to other examples in the guide, or otherwise know to query it.

Leave a Comment