sample from HTML program and PDF book
1. Colons in essays are marks of punctuation used to introduce a strong pause within a sentence. They separates two clauses which could stand alone as separate sentences but which are linked by some relationship in their meaning.
2. A colon is used to introduce a list:
The car has a number of optional extras: sun roof, tinted windows, rear seat belts, and electrically operated wing mirrors.
3. It normally precedes a long quotation or a speech:
Speaking at Caesar’s funeral, Anthony addresses the crowd: “Friends, Romans, countrymen …”
4. It is used before a clause which explains (often by way of illustration) the previous statement. It suggests the sense of ‘That is to say’ or ‘Namely’:
The school is highly regarded: academic standards are high, the staff are pleasant, and the students enjoy going there.
5. It is used to indicate a sharp contrast:
My brother likes oranges: my sister hates them.
6. Note that the colon followed by a dash (:—) is never necessary. Some people put these before a list, but the colon alone is sufficient.
7. The colon is also used between the title and the sub-title of a book:
Magical Realism: Latin-American fiction today.
8. Notice that the items which follow a list are punctuated with commas if they are a succession of individual words.
You will need four ingredients: flour, butter, milk, and sugar.
9. If the items in the list contain clauses or phrases these may be punctuated with semicolons:
You will need the following materials: some scrap paper; a pen, preferably blue or black; some envelopes; and some good, white, unlined writing paper.
10. The colon requires careful handling. If you are in any doubt, use separate sentences.
© Roy Johnson 2003