This article is part of a series about the humble comma, and discusses its role in making sense of lists.

It is unusual to see a (bulleted) vertical list in forms of writing such as novels, newspaper articles, poetry, editorials and op-eds, and dictionary entries; comma-separated lists are used instead. Such lists are referred to as series.

The examples of forms of writing listed above are themselves a series—each element is separated by a comma. The commas are necessary for clarity’s sake—their absence would make parsing the list less easy. For example, the reader might wonder what a poetry editorial is.

The Oxford Comma

Series frequently include compound elements, such as “editorials and op-eds” above.

It used to be common practice to omit the comma between the penultimate and last elements except in cases where either of them were compound elements, but some (not all) style guides advocate the inclusion of that final serial (or “Oxford”) comma.

In my collection of style guides, New Hart’s Rules (UK) and The Chicago Manual of Style (US) encourage its inclusion, while the Canadian Press Stylebook and The Canadian Style both discourage it unless its omission would lead to ambiguity.

Although I write predominantly in Canadian English, my personal preference is for the inclusion of the Oxford comma.

Ampers&s Are Special

If an ampersand appears in a series, it should not be preceded by a comma.

Gowjum, Conman & Fleece is a fictional used-car dealership.

Gowjum, Conman, & Fleece is a fictional used-car dealership.

Ampersands, however, are not normally used in polite company, except in specific situations such as business names. Use the full “and” instead—it’s only two extra keystrokes!

The Key is Konsistency

Whether you embrace or eschew the Oxford comma, the key is to do so consistently. If you choose the latter though, be aware that there are situations where the Oxford comma will still help greatly. Consider the following.

The art and science of imagery can trace its history through such media as holograms, colour film, black and white photographs and paintings.

Are the paintings black and white or not?

Adjective Lists

The black and white question (whose answer is not black or white) leads us nicely into adjective lists.

Although it’s not common for business documents to include adjective lists, I would not be providing a full-enough explanation of how to use commas in lists if I didn’t include any information about adjective lists.

Natural gas is the safe, clean, pure, colourless, inexpensive solution to your performance-related pay challenge. Most companies incent their employees with money. Be different—incent your workforce with gas!

Okay—you may not be the head of a company looking for a non-cash performance incentive for your workforce. The point of that interlude was to show that when you string a bunch of adjectives together, they need to be separated by commas.

But not always.

And this is one of the situations where living with commas gets tricky. Are you sitting comfortably? Then I’ll begin.

In order to decide the comma / no comma question, you need to understand the type of adjectives you’re using. The Chicago Manual of Style and The Canadian Style refer to co-ordinate and non-co-ordinate adjectives. New Hart’s Rules makes the distinction between gradable or qualitative adjectives and classifying adjectives. In the following discussion, I will use both nomenclatures.

Co-ordinate Adjectives

Firstly, let’s make it clear that the word “co-ordinate” is being used here as an adjective meaning “equal in status”.

Adjectives that can be presented in any sequence without affecting the meaning are separated by commas. The natural gas exhortation above is a messy example, but it doesn’t matter which sequence I list the adjectives in—the meaning would be the same. All the adjectives are equal in status—they are co-ordinate.

To put it another way, they are not a mixture of gradable and classifying adjectives.

Non-co-ordinate Adjectives

If a noun is described by two or more adjectives and one (or more) adjective identifies a specific class of whatever the noun is, then the adjectives are not equal in status (i.e., they are not co-ordinate) and don’t need to be separated by a comma.

Political organization and cultural organization are two classes of organization. If you wished to bestow an attribute upon one of these types of organization, you would do so without a comma.

Brits in Space is a successful cultural organization.

The Monster Raving Loony Party is a notable political organization in the UK.

If only all examples were that black and white.

Non-co-ordinate Non-co-ordinate Adjectives

The following is an example from The Canadian Style, and is intended to demonstrate the non-co-ordinate nature of adjectives. However, to me, it demonstrates that not all examples of non-co-ordinate adjectives are equal in status.

A naïve domestic burgundy

The subject is burgundy. The class of wines under discussion is domestic burgundy. The particular wine being singled out is being described as “naïve” and therefore does not need a separating comma.

Just for fun, let’s consider the same statement with the adjectives reversed.

A domestic naïve burgundy

The subject is still burgundy, but now the class of wines under discussion is naïve wines. The particular wine being singled out is a domestic brand. Although the change in meaning is subtle—it’s one of emphasis rather than substance—the meaning has changed.

What if we add a comma?

A naïve, domestic burgundy

The subject remains the same (burgundy), but we aren’t discussing any particular class of burgundy; that particular classification is unimportant in the current context. We are merely describing a particular burgundy as being both naïve and domestic, as though “domestic” was an attribute that is equal in status with “naïve” (or “vinegary” or “amusing” or “unassuming”).

If In Doubt…

The Canadian Style encourages us to omit the comma if we are in doubt. The Chicago Manual of Style characterizes its discussion of the subject as “a general rule”. New Hart’s Rules assures writers that they may “depart from these general principles in order to give a particular effect…”

So what these style guides are telling us is that we’d better know what we’re doing, that their descriptions are only “general rules” or guidelines, and that if we include or omit a comma, we should do so in full knowledge of why we are doing so.

Such is a writer’s lot.

Please Help Improve Yonder Pedant’s Ramblings

• Did I miss a typo? (I’ll feel bad when you tell me, but I’d rather you did tell me!)
• Did I write something that makes you want to turn green and burst out of your shirt?
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