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Compact Oxford English Dictionary for Students

Top 10 Punctuation Tips

If you have a good grasp of punctuation, your writing will flow well and be easy to understand. Here are ten easy-to-remember tips to help you to brush up your punctuation.

You'll find more detailed advice in the dictionary's centre section, and you could also test yourself with this quick quiz.

1. Apostrophes

Apostrophes are used to show belonging. With a singular noun or most personal nouns, add an apostrophe plus s:

The girl's eyes were blue.	(the eyes of the girl)
We met at Ben's party.	(the party given by Ben)
I'll be back in a month's time.	(a period of a month)

TIP: with a plural noun that already ends in -s, add an apostrophe after the s:

The mansion was converted into a girls' school.	(a school for girls)
They might be bankrupt in three months' time.	(a period of three months)

2. Apostrophes

Apostrophes are used to show that letters or numbers have been left out:

It's going to be a hot day.	(short for it is)
They'll be back in two weeks.	(short for they will)
The severe winter of '98.	(short for 1998)

TIP: words like its, hers, yours, and ours (possessive pronouns) are exceptions to the rule about using an apostrophe to show belonging. So, if it's is short for 'it is' or 'it has' (it's going to be a hot day), write it with an apostrophe, but if the meaning is 'belonging to it', then there's no apostrophe:

The bird preened its feathers.
Each case is judged on its own merits.

3. Apostrophes

There are a few special plurals that need an apostrophe, usually to make their meaning clear:

• to show the plurals of letters or numbers, use an apostrophe before the s:

  There are two p's in appear.
  Find all the number 7's.

• use an apostrophe before the s to show the plurals of some very short words, especially when they end with a vowel:

  He was taken aback when the no's overwhelmed the yeses.

TIP: don't use an apostrophe for ordinary plurals of nouns, abbreviations, or dates made up of numbers:

euro	euros
pizza	pizzas
apple	apples
MP	MPs
1990	1990s

4. Colons

Colons are used to mark a break in a sentence that is stronger than a comma. They often introduce something such as a list or quotation.

TIP: the main uses of the colon are:

• to introduce a list:
  
  The job calls for skills in the following areas: proofing, editing, and database administration.

• between two main clauses in cases where the second clause explains or follows from the first:
  
  It wasn't easy: to begin with, I had to find the right house.

• before a quotation and sometimes before direct speech:
  
  The headline read: 'Nuclear scientist goes missing'.
  They shouted: 'Our families are starving. We need land'.

5. Semicolons

Semicolons are used to highlight a pause in a sentence that is stronger than a comma but not as final as a full stop.

TIP: use a semicolon between two main clauses that balance each other and are too closely linked to be made into separate sentences:

An art director searched North Africa; I went to the Canary Islands.

Honey looked up and glared; the man scurried away.

6. Commas

Commas make the meaning of sentences clear by grouping or separating clauses, phrases, or words (there's more information about other uses of the comma in the dictionary's centre section).

TIP: use a comma before and after a clause that begins with 'who', 'which', or 'whom' and that adds extra and non-essential information to a sentence (known as a non-restrictive relative clause):

Jack, who was shivering, wrapped the towel around his waist.
The medical college, which will have three hundred beds, will start functioning next year.

7. Commas

See Tip 6 above for more about commas and clauses.

TIP: don't use a comma if the clause beginning with 'who', 'which', or 'whom' is necessary to understand the meaning of the sentence (known as a restrictive relative clause):

Lots of people who are adopted want to know where they come from.
There are a number of colleges which are fulfilling their welfare duties admirably.

8. Hyphens

One of the main uses of the hyphen is to join two or more words to make a compound word, showing that the words have a combined meaning:

mother-in-law
pick-me-up
hard-hearted

TIP: with compound adjectives such as well known or first class, use a hyphen when the compound comes before the noun:

well-known brands of coffee
a first-class seat

but not when the compound comes after the noun:

brands of coffee that are well known in Britain
a seat in first class

9. Hyphens

See Tip 8 above for more about hyphens and compounds.

TIP: don't use a hyphen between an adverb ending in -ly and a linked adjective, even when they come before the noun:

Many schools offer summer supply teaching to newly appointed staff.
We can offer highly competitive rates to benefit your business.

10. Hyphens

TIP: don't put a hyphen between parts of verbs made up of more than one word (called phrasal verbs), such as set up, let down, or cut off:

The proposal is to set up a local lettings agency in the town centre.
She's been let down by her colleagues.
Our escape route was cut off.

But when a phrasal verb is made into a noun, such as set-up, let-down, or cut-off, then you should use a hyphen:

The authors take readers through the set-up and configuration of sixteen projects.
The film's music is another big let-down.
The US announced a cut-off of economic assistance.