Semicolons — How to Use Them Effectively

Semicolons (;) are punctuation marks used in English to separate independent clauses or series in a sentence. 

However, because semicolons can do the jobs of other punctuation marks such as commas, colons, or periods, semicolons are often misused. 

Let’s dive into the rules for using semicolons, so you can begin employing them confidently in your writing.

Are you unsure if you’ve used semicolons correctly? Use the Originality.ai Grammar Checker to review your content for spelling, punctuation, and grammar mistakes.

Why Should You Use Semicolons?

If semicolons are such a common source of error, why use them? The University of North Carolina at Chapel Hill notes that two common reasons for using semicolons are for style and to highlight the relationship or connection between two sentences. 

A semicolon can be used to join two short sentences and prevent the choppy or abrupt feel of many single-clause sentences in a row. 

In other cases, a semicolon can be used to join two clauses to illustrate a relationship between them, such as cause and effect, contrast, sequencing, or comparison.

Semicolons Join Independent Clauses

Another way to use semicolons is to join two independent clauses that are closely related without a coordinating conjunction. What does this mean in plain language?

• An independent clause is a complete sentence. 
• Without a semicolon or conjunction such as ‘and’ or ‘but,’ these two clauses would create a run-on sentence. 
• Alternatively, each independent clause can also be written as its own sentence.

Examples of semicolons joining independent clauses

First, let’s look at two closely related sentences:

“She loves reading mystery novels. Her brother prefers science fiction.” 

In this example, the topics of the sentences are closely related to one another, because both discuss the siblings’ favorite book genres. 

These two independent clauses can be joined to create one sentence by using a semicolon. 

These sentences can be combined into one phrase and rewritten like this:

“She loves reading mystery novels; her brother prefers science fiction.”

Next, let’s review a sentence with a coordinating conjunction such as ‘and’ where the two clauses are complete sentences. 

“The bakery specializes in pastries and my favorite is the pain au chocolat.” 

The conjunction here can be replaced with a semicolon because both halves of the original sentence are independent clauses. 

The new version of this sentence reads as:

“The bakery specializes in pastries; my favorite is the pain au chocolat.” 

However, the semicolon cannot be used to replace all coordinating conjunctions. 

If the second clause is dependent on the first, the semicolon cannot be used to separate them. 

“She loved to read, but didn’t have much free time.” 

In this sentence, the clause “but didn’t have much free time” lacks a subject. This means the subject of the first clause, “she,” also acts as the subject of the second. A semicolon placed between them would cause a grammatical error in the sentence, forming a sentence fragment. 

How to correctly add a subject to the second clause:

• Incorrect: She loved to read; but didn’t have much free time.
• Correct: She loved to read; she rarely had much free time.

Semicolons Join Independent Clauses with Conjunctive Adverbs

As noted by Purdue University, semicolons can also be used between two independent clauses with a conjunctive adverb such as ‘however’ or ‘therefore.’

A conjunctive adverb shows a relationship between two independent clauses such as cause and effect or contrasting ideas. 

When using a conjunctive adverb, include the semicolon before the adverb and a comma immediately after.

Examples of semicolons joining independent clauses with conjunctive adverbs

Consider two closely related sentences and how they can be combined with a conjunctive adverb:

“The meeting was supposed to start at 10 am. Unfortunately, it was delayed by an hour.” 

In this example, the subject of the second sentence, ‘it,’ relies on the first sentence for context. In this case, a semicolon can be useful to create a more cohesive structure. 

The new sentence would read as follows:

“The meeting was supposed to start at 10 am; unfortunately, it was delayed by an hour.”

In this case, the conjunctive adverb is ‘unfortunately’ it is preceded by a semicolon and followed by a comma.

Let’s look at a second example:

“I wanted to go for a run. The roads were icy.” 

Here, the speaker indicates their desire to go running but adds a contrasting fact that prevents them from going. 

To illustrate the effect the weather had on the speaker’s plans, with a semicolon and the conjunctive adverb ‘however,’ the sentences could be joined as shown: 

“I wanted to go for a run; however, the roads were icy.”

Semicolons May Separate Items in a Series

In a series with internal punctuation or long groupings, use semicolons instead of commas to separate the items in a list. Using semicolons helps the reader to easily identify the separate items. 

Examples of semicolons separating items in a series

Where there is a group of items, semicolons can separate the concepts or ideas, effectively grouping them together:

“The activist discussed the impact of climate change on coastal cities; the necessity of renewable energy for future generations; and the role of governments in enforcing environmental regulations.”

In a series with internal commas, semicolons separate the different items, while commas are used within some or all items: 

“The project requires collaboration between the marketing team, which handles promotions; the IT team, which manages the website; and the sales team, which deals with customers.”

Style guides may suggest alternative approaches for consistent formatting

Keep in mind that company style guides may prefer a particular approach to semicolon use.

For instance, taking the previous example, some style guides may rather this sentence written solely with commas such as:

“The project requires collaboration between the marketing team, which handles promotions, the IT team, which manages the website, and the sales team, which deals with customers.”

Alternatively, a style guide may recommend breaking down a longer sentence like this into a short bullet-point list, for example:

“The project requires collaboration across multiple teams:

• Marketing, which handles promotions
• IT, which manages the website
• Sales, which deals with customers.”

So, the key takeaway? It’s best practice to review your style guide and use that as a reference when formatting a particular piece of content.

Final Thoughts

Although semicolons are a tricky aspect of punctuation, establishing a clear understanding of them can elevate your writing and help you to communicate clearly with your audience.

To review the punctuation in your content, use the Originality.ai Grammar Checker.

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