THE COLON

1. Use a colon after an 'independent clause' to introduce a list.
    

   The most common use of the colon is to introduce both unformatted and bulleted lists. To use the colon correctly in American English, you must make sure that sentence that comes before the colon is a complete, grammatical sentence. One way to test whether you have used a colon correctly is to delete the information after the colon. If what is left can stand alone as a complete thought, then you have a grammatical sentence and have used the colon correctly. In British English, this practice is not always followed, and a colon may be used, even though the sentence before the colon is incomplete.

   COMPLETE SENTENCE COLON The lab report consists of six sections: introduction, background, engineering theory, experimental setup, procedure, and analysis.

    

   Notice in the above example ("The lab report consists of six sections") that you could easily put a period after sections, and everyone would understand the statement as a full sentence. On the other hand, if the information that comes before the colon cannot stand alone, then you shouldn’t use a colon there.

   INCOMPLETE SENTENCE NO COLON! The six main sections of a lab report are: introduction, background, engineering theory, experimental setup, procedure, and analysis. The lab report consists of: introduction, background, engineering theory, experimental setup, procedure, and analysis. The six main sections of a lab report are the introduction, background, engineering theory, experimental setup, procedure, and analysis. The lab report consists of introduction, background, engineering theory, experimental setup, procedure, and analysis sections.

    

   A second important requirement for using a colon to construct a list is to find an appropriate superordinate term that accurately describes the items in the list. Do these items comprise consequences, causes, problems, or some other concept? If you have problems thinking of a superordinate for your list, look up some of the key terms in a good English dictionary; dictionary definitions always describe words in terms of a superordinate concept.

   Superordinate terms are underlined in the examples below.

   The lab report consists of six sections: introduction, background, engineering theory, experimental setup, procedure, and analysis.

   Coral reefs are being destroyed by human activity in many forms: cyanide fishing coral mining deforestation coastal development and careless divers

    

   Common mistakes when using a colon to introduce a list

    

    

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2. Use a colon between 'independent clauses' if the second summarizes, explains or amplifies the first.
    

   Use a colon to connect two independent clauses when the first of the pair creates an expectation in the reader that is fulfilled by the second. then the correct punctuation. In other words the second sentence summarizes, explains, exemplifies or amplifies the first, or provides evidence to prove the preceding statement.

   Note that a capital letter is sometimes used after a colon that precedes an independent clause. Although this seems to be a flexible 'rule', it is best to be consistent in your use.

   The local unemployment rate in Savukoski is quite high: in June it stood at 20%, which was an improvement on the average figure for the early part of the year, which was 24.9%. (explains) The purpose of this paper is twofold: (1) to determine tasks associated with current injury, illness, and fatality trends in the mechanical contracting branches of the construction industry; and (2) to identify current safety practices associated with the reduction of risk of these injuries, illnesses, and fatalities. (explains)

    

   Often the titles of research articles and reports use this function of the colon to give further details explaining the contents of the reports.

   Laser Welding Induced Alignment Distortion in Butterfly Laser Module Packages: Effect of Welding Sequence.

    

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3. Use a colon to introduce an appositive.
    

   Often a colon can be used to introduce an appositive that renames or defines some part of the information that comes before the colon. In this case, the colon acts as a substitute for a word like i.e. or a phrase like that is to say.

   What Germany's chancellor sees in the creator of the Windhorst Tower, a 220-storey landmark in Vietnam's Ho Chi Minh City, is a paragon of his country's scarcest resource: entrepreneurship.

    

   A colon can also be used in this appositive sense to introduce a rule or principle.

   Always apply the Golden Rule: Do unto others as you would have others do unto you.

    

    

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4. Use a colon to introduce a quotation.
    

   When quoting others' words in a direct quotation, you have two choices about how you present these words: either enbedded within the normal flow of your text (integrated quotes) or outside your text (blocked quotes). Integrated quotes incorporate the quote within a single sentence and generally require a comma (examples A and B), or no introductory punctuation (example C) when enbedded into the structure of the sentence.

   Integrated quotes (Comma) "These diseases mainly affect younger age groups, so that the total burden of disease due to climate change appears to be borne mainly by children in developing countries," said Andrew Haines, professor at the London School of Hygiene and Tropical Medicine. Haines said, "These diseases mainly affect younger age groups, so that the total burden of disease due to climate change appears to be borne mainly by children in developing countries." Haines said that malaria and malnutrition "...mainly affect younger age groups, so that the total burden of disease due to climate change appears to be borne mainly by children in developing countries."

    

   To use a colon to introduce a direct quotation, the information before the colon should not only be a complete sentence but it should add to the reader's understanding of the quotation by either explaining something about the quote or summarizing the purpose or contents of the quote.

   Block quotation (Colon) Haines predicts that the effects of climate change will be greater in the developing world: These diseases mainly affect younger age groups, so that the total burden of disease due to climate change appears to be borne mainly by children in developing countries.

   Integrated quotation (Colon) Mr Smith's old company was based in the Thames Valley, one of Europe's technology hubs, with no apparent ill effects. However, for his new company, Smith was worried about the business-card effect: "If a customer meets two business people, each with equally good technology, he will still take the one based in America more seriously than the Euro­pean one."