Using Lists—Horizontal Lists

Our previous article, ‘Using Lists—Vertical Lists’, outlined how to create emphasis in your writing through effective construction of lists.

What happens if you have a list, but don’t want that much emphasis or visual signposting? What if you don’t have the physical space to present dot points?

Horizontal lists, lists that appear within written text, present a series of items without promoting the items as priority on the page (as a vertical list does).

There are three punctuation marks that are particularly useful when presenting lists: the colon, the semicolon and the comma. We’ll explain the role of each of these punctuation marks in this article.

The Colon

The colon always introduces a vertical list; however, it is not always necessary in a horizontal list. For example:

Julia Gillard has held the title of prime minister, leader of the Labor Party and Minister for Education.

A colon is always used following appositions (e.g., ‘the following’ or ‘as follows’). Here’s the same sentence rewritten:

Julia Gillard has held the following titles: prime minister, leader of the Labor Party and Minister for Education.

A colon isn’t needed if the series of items flows naturally (as it did in the first example). The colon is often unrequired when the following expressions do its job: ‘including’, ‘namely’ and ‘such as’. In this case, a comma will suffice. For example:

Julia Gillard has held many titles, including prime minister, leader of the Labor Party and Minister for Education.

One word of warning though—do not introduce a list with a semicolon. If you need a punctuation mark to introduce a list, the colon is the punctuation mark you need.

The Semicolon

Now that we know that semicolons can’t introduce lists, you might be asking what they can do.

Semicolons are used to separate items in complex lists. You often need a semicolon between items when there are commas within the items themselves. Let me explain with an example:

Four aspects will be considered: time in classroom; experience, with specific attention to paid experience; rate of pay; and reported level of support.

The semicolon is quite effective in separating items in the list. It’s important to point out that if you’re using semicolons to separate items in a list, a semicolon is used before the ‘and’ that leads to the final item. If a comma had been used to separate the items in the list, we wouldn’t put a comma before ‘and’ unless it was necessary to avoid ambiguity. A comma before the ‘and’ is called the ‘serial comma’; it’s not used in British/Australian English.

The Comma

The comma is also used to separate items in a list. You can see the comma at use in our first example, repeated here:

Julia Gillard has held the title of prime minister, leader of the Labor Party and Minister for Education.

You’ll notice a comma isn’t normally placed before the ‘and’. There is one exception: a serial comma should be used when necessary to avoid ambiguity.

I have invited the following people to the conference: Dr and Dr Walker, Mrs Hudson, Mr Jones and his friend, and the office secretary.

The comma after friend avoids confusion between Mr Jones’s friend and the office secretary. Without the comma, the item of the list might read more like ‘Mr Jones’ friend’ who is also ‘the office secretary’. This way, the serial comma distinguishes them as separate items—and people!

If you’d like to learn about how to write vertical lists, we recommend you read our article, ‘Using Lists—Vertical Lists’.