Colons & Semi-Colons

Writers frequently misuse the colon and the semi-colon.

  • Semi-colons separate elements of a series where at least one element contains a comma and separate independent clauses as an alternative to using a comma and a conjunction.
  • Colons indicate that the material following is an explanation, illustration, example, or reason for the material that preceded the colon.

Semi-colons: between elements in a series

When an element in a series of three or more contains a comma, a semi-colon serves to clearly separate the three elements.

Ex: The pig likes organic carrots, which I grow at home; potatoes, which I purchase at the market; and any scraps, as long as they are not pork or bacon. 

The semi-colons make it clear which items are in the series and which are dependent clauses that describe the listed items.

Semi-colons: between independent clauses

Perhaps the most common way to separate two independent clauses is by using a comma followed by a conjunction.  The same function can be served by a semi-colon.

Ex: Hillary Rodham Clinton is an outspoken advocate for children’s rights; her opinions often garner the attention of a critical media.

Colons: followed by a  “reason” or explanation

Colons can be used to precede the explanation of a statement.

Ex: There was only one reason the professor would have to email me: to request the overdue essay.

Colons: introducing a list

Colons can also be used to introduce a list.  This following example is a direct quotation from page 199 in Harris.

Ex: The school offered four alternatives to the physical education requirement: yoga, cycling, ballet and jazzercise.