coordinate elements, serial commas

Elements of equal rank or relation in a sentence are said to be coordinate. The coordinate elements may be words or phrases in a series, or they may be entire clauses.

Words, phrases and dependent clauses

Items in a series may be separated by commas:

• Complacency, urbanity, sentimentality, whimsicality

They may also be linked by coordinating conjunctions such as and or or:

• the good, the bad and the ugly
• economists, sociologists or political scientists
• On his camping trip, Nathan slept in a tent, cooked over a fire and canoed for miles.
• Cheryl didn’t explain where she had gone, what she was doing or when she would be back.

Omitting the final comma

Opinions differ on whether and when a comma should be inserted before the final and or or in a sequence. In keeping with the general trend toward less punctuation, the final comma is best omitted where clarity permits, unless there is a need to emphasize the last element in the series. This comma is usually omitted in the names of firms and always before an ampersand:

• Cohen, Hansen and Larose
• Deeble, Froom & Associates Ltd.

On the other hand, it is usually inserted if the items in the series are phrases or clauses of some length, if emphasis is desired, or if omission of the comma might lead to ambiguity or misunderstanding:

• She embraced him once again, turned away, and then walked out the door forever. [comma for emphasis]
• Tenders were submitted by Domicile Developments Inc., East End Construction, Krista, and Ryan and Scheper. [comma for clarity]

A comma is also required before etc.:

• He brought in the wine, the glasses, etc.

Appositives with coordinate elements

A more complex situation occurs when apposition commas are used together with coordinating commas, as illustrated below:

• Carla Tavares, a recent MBA graduate, three students and a technician set up the experiment.

The sentence should be rephrased so that no non-restrictive appositive occurs within a coordinate element:

• A recent MBA graduate named Carla Tavares, three students and a technician set up the experiment.

Alternatively, semicolons may be used to separate elements in a complex series:

• Jane Stewart, MP for Brandt, Ont.; Stan Keyes, MP for Hamilton West, Ont.; John Nunziata, MP for York-South Weston . . .

Independent clauses

A comma is normally used to separate two main clauses in a compound sentence when they are joined by a coordinating conjunction (and, but, or, nor, yet or for):

• “They are often called individualists, and in economic matters they were, but in social matters, the dominating concept was that of good neighbourliness.” (M. M. Fahrni)

If the clauses are short or closely related, the commas may be omitted before and, but, or or nor:

• He opened the letter and then he read the contents.
• Life is short but art is long.

Coordinate clauses not joined by a coordinating conjunction are usually separated by a heavier mark of punctuation than the comma:

• “Canadian poetry must now be judged by achievement; it does not need to be criticized for not being like other poetries.” (Margaret Atwood)

A comma will suffice, however, if the clauses are short, or if the writer wishes to emphasize a contrast or lead the reader on to the following clause as quickly as possible:

• There are good regulations, there are bad regulations.
• It was not the duration of the pilot project that caused concern, it was the size of the project team.

It is a common error to confuse a simple sentence having a compound predicate with a compound sentence requiring a comma between clauses. Note the difference between the following examples:

• She investigated the matter and then wrote a detailed report.
  (simple sentence)
• She investigated the matter, and then the committee began its work.
  (compound sentence)

Where the clauses of a compound sentence are joined by a conjunctive adverb (such as however, instead, meanwhile, otherwise, similarly, so, still, then, therefore or yet), a semicolon is called for:

• The climbers had planned to scale the rock face; however, it was too sheer.

Adjectives

A series of adjectives modifying a noun may or may not be coordinate. The adjectives are coordinate if their order does not affect the meaning, in which case they should be separated by a comma. If they are not coordinate, that is, if one adjective modifies the phrase formed by the following adjective(s) plus the noun, then they should not be separated by a comma:

• a rich, creamy sauce

but

• a naive domestic burgundy

Adjectives of both types may of course occur together:

• a tender, succulent young chicken

The rule stated above, however, is not an infallible guide. When in doubt omit the comma, as in:

• The plain honest truth is that he is a liar.

The final adjective in the series should not be separated from the following noun by a comma:

• Nations require strong, fair, open, decisive government.

Antithetic expressions

Antithetic expressions are usually separated by a comma:

• This proposal is not to be tossed lightly aside, but to be hurled with great force.

However, short expressions of this type may not require a comma:

• The more wit the less courage.

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