A common use for the colon is to precede a list.

“Chapter Three examines the performance potentials for three different types of air-source heat pump: single-stage, variable-speed centrally ducted, and variable-speed ductless heat pumps.” (Szekeres, 2019)

However, do not use a colon when the list is a necessary part of the sentence. In grammatical terms, a colon should not be placed between a verb and its complement, or a preposition and its object. In other words, do not use a colon to separate words that function together. Here are two incorrect examples:

Three research methods are: qualitative, quantitative, and mixed-methods.

(Here, the colon separates the verb “are” and its complement “qualitative,” etc.)

We examine the advantages and disadvantages of: qualitative, quantitative, and mixed research methods.

(Here, the colon separates the preposition “of” and its object “qualitative,” etc.)

Colons should be used sparingly as a means of introducing single-sentence quotations. Rather, try to integrate the quotation into the syntax of your sentence. For example, although the following sentence is grammatically correct, the style is a little choppy; the colon forces an independent clause before it, which stops suddenly before the quoted content.

Letizia Treves notes a milestone in Artemesia Gentileschi’s career: “It was in Florence, after all, that she became the first female member of the Accademia delle Arti del Disegno (in 1616) and established her reputation.” (Avery-Quash, 2019)

In the second version of the sentence, the syntax, and hence the ideas, flow more naturally.

Letizia Treves notes, “It was in Florence, after all, that she became the first female member of the Accademia delle Arti del Disegno (in 1616) and established her reputation.” (Avery-Quash, 2019)

A semicolon should not appear before coordinating conjunctions—linking words such as and, or, but, so, for, yet—which are preceded by a comma.

Using in-text citations is a good start; but you should also include all sources in your list of references.

The “but” above should be preceded by a comma, not a semicolon.

However, a semicolon may take the place of one of these joining words, lending equal conceptual weight to the linked expressions, because both clauses are now independent.

Using in-text citations is a good start; you should also include all sources in your list of references.

The semicolon takes the place of coordinating conjunction “but.”

When a conjunctive adverb (e.g., however, nevertheless, therefore, thus) or a transitional phrase (e.g., for instance or in fact) appears between two independent clauses, it must be preceded by a semicolon, and is usually followed by a comma.

In Anne-Marie MacDonald’s novel Fall On Your Knees, Frances Piper eventually learns the truth about her family history; however, her sister has difficulty believing her.

Exceptions

Generally, semicolons are placed only between two independent clauses. However, there is one exception to this rule. While semicolons are never used to introduce a list, they are conventionally used to separate lengthy items within a list, especially when individual items contain internal punctuation (i.e., a comma). This convention saves confusion about which words logically belong together.

This week, I had a lot of papers due: one on evolutionary biology, which was interesting; one on early 20^th c films, which I had trouble writing; one on social justice; and one on poverty and addiction, which was fifteen pages long.