Punctuation

Semicolons

Semicolons separate two sentences—or what would be two sentences, if a period appeared instead of the semicolon. It’s sometimes said that if periods are like stop signs, then semicolons are like yield signs: we aren’t required to stop, but the meaning of the text won’t be misconstrued if we do.

Semicolons can be used, also, in lists of long items, to clarify where one list item ends, and the next begins.

Rule 1: Except in lists, the text should have identical meaning regardless of whether a semicolon or a period is used.

Example: On 12 January 2007, The Globe and Mail Web columnist commented on the growing use of wikis other than Wikipedia: “While Wikipedia has propelled the wiki concept to worldwide prominence, there has always been interest in harnessing it for other projects; projects less ambitious in scope than creating a complete encyclopedia of everything in existence.”

What’s wrong: The clause following the semicolon cannot stand on its own; instead of a semicolon, a period should be used. As an alternative, an em dash could be used.

Correct usage: “… there has always been interest in harnessing it for other projects, projects less ambitious in scope than creating a complete encyclopedia of everything in existence.”

Alternative usage: “… there has always been interest in harnessing it for other projects—projects less ambitious in scope than creating a complete encyclopedia of everything in existence.”

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