English punctuation: How to use semicolons

Good punctuation is fundamental to good writing. Many of us take commas, periods, question marks, and exclamation marks for granted. We barely notice them, or how they affect the mood and rhythm of a short story, an article, an email, a book, or any written composition. Punctuation marks are tools that help give shape and clarity to our writing. Put another way, they are the Swiss army knives of a writer's toolkit.

How? They can cut off; they can connect; and they can carve around the words on a page. If you learn how to use them well, you can take a bloated sentence and turn it into poetry, or turn a bunch of simple sentences into a flowing paragraph.

One of the most useful of these tools, but also one of the most misunderstood, is the semicolon. While some writers and grammarians argue that semicolons are useless and needless--Why use one when a period will suffice?--semicolons are nonetheless a part of English punctuation, and they can add variety and needed clarity to your academic and professional writing.

So, how and when do we use semicolons? In short, they serve three main functions:

1. to separate long lists of items, especially when those items involve commas.

2. to separate independent clauses that are joined by conjunctive adverbs.

3. to separate independent clauses that contain closely related ideas.

Let us look at these functions one at a time with multiple example sentences.

1. Separating long lists of items, especially when those items involve commas

Example:

We traveled to many cities on our vacation, including Bilbao, Spain; Paris, France; and Berlin, Germany.

While we also use commas to separate three or more items on a list, they would make this sentence far too confusing. Take a look:

We traveled to many cities on our vacation, including Bilbao, Spain, Paris, France, and Berlin, Germany.

Are Bilbao, Spain, Paris, France, Berlin, and Germany all separate places? Obviously not, but using commas makes the sentence look messy. Therefore, a semicolon is essential for clarity in this sentence. This usage of the semicolon is common when we are listing objects, locations, descriptions, and names. Here are a few more examples:

I.

Mila walked into the room and was disgusted by what she saw: uneven piles of books, each one in a different corner of the room; half-eaten chocolate bars, their wrappers rudely torn; a statue of a naked man, the words "This is art" scratched across his chest in red marker; and her former husband sleeping on the bed, his cheeks red and his face unshaven.

II.

The line of suspects included Mark Coleman, the disgraced son of a banker; Donald Parker, the man responsible for the previous month's bank robbery; and Greg Malloy, a local criminal who had more arrests to his name than one could count.

III.

Donna thought of the gifts from her seventh birthday: the green dollhouse, which she had received from aunt Linda; the rainbow-coloured dress, which had been given to her by her mother; the red socks, a last-minute gift from her uncle Troy; and the art kit, given to her by the only person who truly understood her.

2. Separating independent clauses joined by conjunctive adverbs.

Example:

The developers realized they had made a fatal error in the design of the bridge; consequently, they had to delay construction until the error was addressed.

In this case, you could argue for the use of a period instead of a semicolon, and that would be your right. This is one of the two cases where the matter of style comes into place. Here is the same sentence with a period:

The developers realized they had made a fatal error in the design of the bridge. Consequently, they had to delay construction until the error was addressed.

When you read these two examples one after the other, the one with the semicolon should feel like it has a more connected flow. Whether that is because a semicolon requires a shorter mental pause than a period, or because the c in consequently is written in lowercase, and therefore makes the second half of the example feel like it is part of one string of ideas, the effect is the same: The semicolon creates a stronger sense of unity while the period creates a more definitive break. In the end, this really does come down to a style choice. Here are a few more examples:

I.

We wanted to arrive early; unfortunately, traffic prevented us from doing so.

OR

We wanted to arrive early. Unfortunately, traffic prevented us from doing so.

II.

The hospital was already overloaded with patients; as a result, we had to find another option.

OR

The hospital was already overloaded with patients. As a result, we had to find another option.

III.

The CEO was forced to step down; nevertheless, the decision had come too late, and the company declared bankruptcy just five months later.

OR

The CEO was forced to step down. Nevertheless, the decision had come too late, and the company declared bankruptcy just five months later.

3. Separating independent clauses that contain closely related ideas.

Example:

Her heart wasn't in it anymore; she knew she needed to make a change.

This is another case where a period is also fine. However, due to the relative "lightness" of a semicolon in comparison to the "heaviness" of a period, separating two complete thoughts such as these with a semicolon adds a stronger sense of unity between the ideas. Here are the same two sentences with a period:

Her heart wasn't in it anymore. She knew she needed to make a change.

You can argue which set of sentences feels more dramatic, but both are possible. In brief, you can use the semicolon when you want to give the two sentences equal emphasis. Just remember that you typically should not use a coordinating conjunction after a semicolon. (Ex: I fell; but I was fine.) The two sentences on either side of the semicolon must be closely related to one another, and they must be independent clauses, which means they must express complete thoughts. Here are a few more examples:

I.

Valeria knew what she had to do; she just did not know if she had the courage to do it.

OR

Valeria knew what she had to do. She just did not know if she had the courage to do it.

II.

The report had several errors; Ayano knew it would probably be rejected.

OR

The report had several errors. Ayano knew it would probably be rejected.

III.

Thank you for meeting with me yesterday; I found our exchange quite productive.

OR

Thank you for meeting with me yesterday. I found our exchange quite productive.

That is all for semicolons. I hope you have found these explanations useful, and that you will be able to use semicolons more confidently in your own writing. My final piece of advice is this: Don't overdo it. What do I mean? Do not use semicolons after every single sentence. If you use them too often, your writing can look, in a word, strange. Be prudent, be judicious, and make good use of your new knowledge.

Until next time, I wish you success in your writing.