Colons and Semicolons

Colons

The colon is the most abrupt piece of punctuation; it brings the sentence to a screeching stop. It must always be preceded by an independent clause (i.e., a complete sentence), which would require a period if it were to stand on its own.

The colon may be followed by a phrase, a list, a quotation, or even another independent clause.

Remember what our TA said: “Practice academic integrity.”

Colons are also commonly found in the titles of academic books and articles:

“Ancient orphan crop joins modern era: gene-based SNP discovery and mapping in lentil” (Sharpe, et. al., 2013).

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)

Semicolons

The semicolon is a misused and misunderstood piece of punctuation. Essentially, semicolons exist only to join independent clauses (i.e., complete sentences). Picture it as a period sitting on top of a comma. The period signals that the semicolon must be preceded by an independent clause; the comma indicates that the semicolon intends to link related elements into a single sentence.

It’s important to follow academic integrity rules; otherwise, there are serious consequences.

Do not use a semicolon between unequal parts of a sentence, such as between independent and dependent clauses, where a comma is called for:

It’s important to follow academic integrity rules; because otherwise, there are serious consequences.

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.

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 20th c films, which I had trouble writing; one on social justice; and one on poverty and addiction, which was fifteen pages long.

We encourage you to further explore this topic via the articles and books under “References” below.

Avery-Quash S., Treves L., & Whitlum-Cooper F. (2019). “[In]Visible: Paintings by Women Artists in the National Gallery, London: An Interview with Letizia Treves and Francesca Whitlum-Cooper.” 19: Interdisciplinary Studies in the Long Nineteenth Century 1(1).

MacDonald, A. (1996). Fall On Your Knees. Knopf Canada.

Sharpe, A.G., Ramsay, L., Sanderson, L., Fedoruk, M.J., Clarke, W.E., Li, R., Kagale, S., Vijayan, P., Vandenberg, A., Bett, K.E. (2013). Ancient orphan crop joins modern era: gene-based SNP discovery and mapping in lentil. BioMed Central Ltd BMC Genomics, 14(1), p.192-192.

Szekeres, A.J. (2019). Electrification of home heating in Ontario with the air-source heat pump. [Doctoral dissertation, Queen’s University].