When do you use a semicolon?

The most common use of a semicolon is to join two independent clauses that share a strong connection. An independent clause is a group of words that can stand on its own as a complete sentence. Imagine two cars driving side by side on a highway; they are separate but traveling together. Instead of putting a hard stop (period) between them, a semicolon shows the reader that the ideas are intimately linked. For example: 'The sky grew dark; the storm was approaching.'

Often, you will use a semicolon when you bridge two independent clauses with a conjunctive adverb (words like 'however', 'therefore', 'moreover', or 'consequently'). The semicolon goes before the conjunctive adverb, and a comma goes right after it. This structure gives your sentence a formal, logical flow. For example: 'I studied for three hours; therefore, I felt prepared for the exam.'

Semicolons act as 'super-commas' when you are dealing with a complicated list. If the individual items in your list already contain commas (like a city and state), using more commas to separate the items will confuse the reader. The semicolon steps in to clearly mark the boundary between the main items. For example: 'We visited Paris, France; Rome, Italy; and Madrid, Spain.'

A common mistake is using a semicolon with a coordinating conjunction (for, and, nor, but, or, yet, so). If you have one of these words connecting two complete sentences, you only need a comma, not a semicolon. Another frequent slip-up is capitalizing the word immediately following the semicolon. Unless that word is a proper noun (like a name or place) or the pronoun 'I', it should always be lowercase.