If you want your written English to be more effective and elegant, you should use the colon and semicolon correctly. While they may appear to be similar, they have very different uses. In brief, the colon is used to provide a pause before introducing related information, while the semicolon is merely a break in a sentence that is stronger than a comma but not as final as a full stop
- Do not use a colon in a complete sentence after phrases such as ‘including’, ‘such as’, and ‘for example’. Phrases like these already indicate to the reader that a list of examples will follow, there is no need to introduce them with a colon; it would be redundant.
Incorrect: New Zealand has many types of fruit, such as: apples, nashi pears and grapes. Correct: Many birds are found in New Zealand including kiwi, tui, weka and kea.
- Do not use a colon after a preposition (such as ‘in’), or a verb, that introduces a list.
Incorrect: The medical student excelled in: surgery, diagnostics and trauma. Correct: The new law student excelled in surgery, diagnostics and trauma.
- Do use a colon to introduce an item or a series of items, or provide an explanation, but only if its use is not contrary to rules 1 and 2 above.
Do not capitalise the first item after the colon in a list (unless it’s a proper noun). Correct Use to Introduce a List: The store carried all the items the new teacher needed: pens, paper, printer toner and folders. Correct Use as an Explanatory Tool: The cafeteria served the type of food most preferred by students: noodles.
- A colon instead of a semicolon may be used between independent clauses when the second sentence explains, illustrates, paraphrases, or expands on the first sentence.
Correct: He got what he worked for: he really earned his retirement.
- If the material following the colon is a dependent clause or phrase, do not capitalise the first word (unless it’s a proper noun).
Correct: He got what he worked for: a happy retirement.
- Do use a colon when restating an idea. If the material following the colon constitutes a full sentence, you can choose to capitalise the first word or not. Some writers and editors feel that capitalising a complete sentence after a colon is always advisable. Others advise against it.
Correct: Remember the old adage: Pretty is as pretty does.
- When two or more complete sentences follow a colon, capitalise the first word following the colon.
- Also, capitalise the first word of a complete or full-sentence quotation that follows a colon.
Correct: Mother announced to all present: “Mary is getting married.” Correct: The teacher gave us three rules to follow: Be on time. Work hard. Share your knowledge.
- The colon can be used to emphasise a phrase or single word at the end of a sentence. An em-dash can be used for the same purpose.
Correct: After three weeks of deliberation, the jury finally reached a verdict: guilty.
