Punctuation

by Craig Shrives

How to Use Punctuation

Punctuation is the use of conventional characters (e.g., commas, semicolons) to improve clarity. In general, punctuation aids comprehension by showing a reader which words are grouped and where to pause.

Table of Contents

  • The Main Punctuation Marks
  • Punctuation Use and Examples
  • Apostrophes
  • Colons
  • Commas
  • Hyphens
  • Parentheses (Round Brackets)
  • Square Brackets
  • Period (Full Stop)
  • Semicolons
  • Quotation Marks
  • Printable Test
punctuation English grammar

The Main Punctuation Marks

Here are the main punctuation marks in English grammar:

Punctuation Use and Examples

Below is a handy summary of how each of the main punctuation marks is used. There are easy examples as well as links to pages offering more detail and more examples.

Apostrophes

Apostrophes are used:

  1. To show possession
    • one dog's kennel, two dogs' kennel
  2. In time expressions
    • a day's holiday, two weeks' pay
  3. In contractions
    • can't, don't, isn't

Apostrophes are NOT used:

  1. To show plurals
    • three dog's wrong cross, two patio's wrong cross
  2. Randomly before the letter s
    • She like's cakes. wrong cross
Read more about using apostrophes.

Colons

Colons are used:

  1. To extend a sentence to expand on something previously mentioned in the sentence
    • I need just one personal trait: loyalty.
  2. After an introduction
    • I've seen the following: rust, slime, and a rat.
  3. In references, times, and titles
    • Read Genesis 1:1 before 09:00.
  4. With quotations
    • He said: "Laugh at yourself first, before anyone else can."
Read more about using colons.

Fun Widget

Before we look at the other types of punctuation, here is a widget that shows 50 writing mistakes involving punctuation:
50 Punctuation Errors
Number /50
(Apostrophes Section)
The Error
An Example
How serious is this error?
Safe Meh Oops Eek

Commas

A comma is used:

  1. After setting the scene at the start of a sentence
    • Now she is wiser, she understands.
  2. After transitional phrases like However, Consequently, or As a result
    • However, I now agree with you.
  3. After an interjection
    • Crikey, it's true!
  4. Before a conjunction joining two independent clauses
    • She likes pies, and she likes cakes.
  5. As parentheses
    • Peter and John, who live next door, love my pies.
  6. To separate list items
    • bread, honey, and jam
  7. After a long subject if it helps the reader
    • A, B, C, and D, are essential qualifications.
  8. In numbers
    • 2,515
  9. With the vocative case
    • I know your uncle, Sarah.
  10. Before a quotation
    • She whispered, "I know."
Read more about using commas.

Hyphens

Hyphens are joiners. They are used:

  1. To join the words in a compound adjective
    • seven-foot table, silver-service banquet
  2. To join the words in compound nouns
    • paper-clip, cooking-oil
  3. To join prefixes to words
    • ultra-expensive, re-establish
Their main purpose is to show the joined words are a single entity (e.g., a single adjective or a single noun). They are also useful to avoid ambiguity (e.g., a hyphen makes it clear that a paper-clip is a clip for paper and not a clip made of paper). Read more about using hyphens.

Parentheses (Round Brackets)

Round parentheses (round brackets) are used:

  1. To insert extra information (often an afterthought, clarification, or expansion of a recently mentioned idea)
    • Set in the 17th century, The Three Musketeers ("Les Trois Mousquetaires" in French) is a novel by Alexandre Dumas.
  2. To present a plural option with a singular one
    • Your guest(s) must leave before midnight.
Read more about using round parentheses.

Square Brackets

Square parentheses (square brackets) are used:

  1. To make quoted text clearer by expanding on or replacing part of the quote.
    • If you don't like them [my principles], well, I have others.
  2. To make it clear that terms like [sic] and [...] are insertions by the current author not the originator.
    • In your statement, you wrote: "I appraised [sic] him of the situation at about 4 o'clock."
Read more about using square parentheses.

Period (Full Stop)

A period (.) (or full stop in the UK) is a punctuation mark used:

  1. At the end of a declarative sentence
    • I eat pies.
  2. At the end of an imperative sentence (which is not forceful enough for an exclamation mark)
    • Please use the bathroom upstairs.
  3. In an abbreviation (including initialisms and contractions)
    • B.B.C., Prof.
Read more about periods (full stops).

Semicolons

Semicolons are used:

  1. In lists when the list items contain commas
    • Peter, the officer in charge; Colin, the chef; and Heidi, my dog
  2. To create a smoother transition between sentences, particularly when the second starts with a phrase like however or as a result
    • It was freezing; however, we still enjoyed it.
  3. Before a conjunction which merges two sentences containing commas
    • Yesterday, it was, to our surprise, sunny; but today, as expected, it's dull.
Semicolons are not used for introductions (e.g., I would blame one thing for my divorce; beer. It should be a colon.) Read more about using semicolons.

Quotation Marks

Quotation marks (or speech marks as they're also called) are used:

  1. To show the exact words spoken or written
    • Reagan said: "You can tell a lot about a fellow's character by his way of eating jellybeans."
  2. For the names of things like ships, books, and plays
    • I was certain the "Spruce Goose" was too heavy to fly.
  3. To express the idea of alleged or so-called
  4. (During the speech, his "mates" slipped out the side door.
Read more about using quotation marks.

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