How to use a colon?

The colon like the comma is a commonly misused piece of punctuation that is usually confused with the semicolon. Quite often it is overused, a colon should only be used sparingly.

What are the functions of a colon?

• To introduce a list within a sentence
• To introduce an idea within a sentence
• To introduce quoted material within a sentence

How to use a colon to introduce a list within a sentence

A colon can be used to introduce a list of series of items. The first item in the list that appears after a colon does not need to be capitalised, unless it is a proper noun. When using a colon the clause that precedes it must make sense with its corresponding list.

Frodo had packed everything he needed: food, drink, maps and sunglasses.

The clause, Frodo had packed everything he needed, makes sense on its own and so a colon  can be introduced after it.

Avoid using a colon to introduce a list when it directly follows a verb or preposition.

I need: dragon's blood, fairy smiles and pixie dust.

Instead you should write

I will need the following: dragon's blood, fairy smiles and pixie dust.

How to use a colon to introduce an idea within a sentence

Two independent clauses can be linked together by a colon if the second clause explains, illustrates, paraphrases or expands on the first independent clause.

He got what he deserved: eternal damnation.

As with using a colon to introduce a list within a sentence the first clause of the sentence when introducing an idea should also be a stand alone clause.

How to use a colon to introduce quoted material within a sentence

A colon can be used after a clause to introduce quoted material.

The witch reminded her apprentice from the famous quote in the book of shadows: 'Harm ye none, do what thy will.'