Commas with coordinate elements

On this page

• General information
• Words, phrases and dependent clauses
  • Serial commas
  • Appositives with coordinate elements
• Independent clauses
  • Coordinate clauses with no coordinating conjunction
  • Compound sentences
• Adjectives
• Antithetic expressions
• Additional information

General information

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

In standard prose, items in a series are usually linked by coordinating conjunctions such as and or or:

• My favourite animals are dogs, horses and giraffes. [series of words]
• On his camping trip, Nathan slept in a tent, cooked over a fire and canoed for miles. [series of phrases]
• Cheryl didn’t explain where she had gone, what she was doing or when she would be back. [series of dependent clauses]

Items in a series may be separated only by commas for literary effect:

• “These griefs, these woes, these sorrows make me old.”

A comma is required before etc.:

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

Serial commas

The serial comma (also known as the Oxford comma or the Harvard comma) is a comma inserted before the final and, or or nor in a sequence of three or more elements. Opinions differ on whether it should be used.

In keeping with the general trend toward less punctuation, the serial comma is best omitted where clarity permits:

• We saw Alex, Patricia and Tom at the concert. [no comma required before and]
• Tenders were submitted by Maple Crest Developments Inc., North Shore Builders, Krestel, and Ryan and Scheper. [comma required for clarity]

The serial comma is usually omitted in the names of firms and always before an ampersand:

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

The serial comma is usually inserted if the items in the series are phrases or clauses of some length, if emphasis is desired or if omitting the final comma might lead to ambiguity or misunderstanding:

• He promised to finish the report following the meeting on Friday, to review the new budget proposals over the weekend, and to prepare the committee presentation for Monday. [comma inserted to separate long phrases]
• She embraced him once again, turned away, and then walked out the door forever. [comma inserted for emphasis]
• I dedicated my latest novel to my parents, Emily Brontë, and Victor Hugo. [comma inserted to avoid misunderstanding]

Appositives with coordinate elements

A more complex situation occurs when apposition commas are used together with coordinating commas:

• Aidan Hawe, 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 Aidan Hawe, three students and a technician set up the experiment.

In a complex series containing appositives, semicolons may be used rather than commas to separate elements:

• Steve Poutré, Governor General’s Literary Award (French-language fiction, 2024); Ma-Nee Chacaby, Canada Reads (2025); Joseph Boyden, Giller Prize (2008); Catherine Banks, Governor General’s Literary Award (English-language drama, 2008 and 2012) …

Independent clauses

A comma is normally used to separate two independent clauses in a compound sentence when they are joined by a coordinating conjunction:

• They wanted to go shopping, but nothing was open that day.
• He didn’t confirm his attendance, nor did he apologize for his late arrival.
• We can stay in and make something for dinner, or we can go try that new restaurant we’ve been hearing about.

If the clauses are short or closely related, the comma 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 with no coordinating conjunction

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

• She knocked on the door for what seemed like hours; there was no answer from inside the house.

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.

Compound sentences

It’s a common error to confuse a simple sentence containing a compound predicate with a compound sentence requiring a comma between independent clauses:

• She investigated the matter and then wrote a detailed report. [simple sentence with a compound predicate]
• She investigated the matter, and then the committee began its work. [compound sentence requiring a comma]
• Alan packed sandals, shorts and T-shirts but forgot socks and sunscreen. [simple sentence with a compound predicate]
• Alan packed sandals, shorts and T-shirts, but he forgot to pack socks and sunscreen. [compound sentence requiring a comma]

A comma may sometimes be required to avoid misunderstanding:

• She thanked the waiter who brought her meal, and smiled.

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 required:

• The climbers had planned to scale the rock face; however, it was too sheer.
• We wanted to visit our family; instead, we spent the holidays at home.

Adjectives

A series of adjectives modifying a noun may or may not be coordinate.

The adjectives are coordinate if their order doesn’t affect the meaning, in which case they should be separated by a comma:

• a rich, creamy sauce

If they’re cumulative rather than 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 naive domestic burgundy

Adjectives of both types may occur together:

• a tender, succulent young chicken

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

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

A comma should not separate the final adjective in the series from the noun that follows it:

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

Antithetic expressions

Expressions that contain seeming contradictions within a balanced grammatical structure are usually separated by a comma:

• This proposal is not to be tossed lightly aside, but to be hurled with great force.
• She gave a brief, yet thorough, explanation for the committee’s decision.
• The client wanted the senior architect, not the intern, to design the new building.

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

• The more wit the less courage.

Additional information

• Coordinating conjunctions
• Commas with appositives
• Complex sentences
• Compound sentences
• Simple sentences
• Conjunctive adverbs
• Controlling emphasis: Coordination and subordination (Peck’s English Pointers)
• Commas that clutter: Unnecessary commas (Peck’s English Pointers)
• Commas that count: Necessary commas (Peck’s English Pointers)

Quizzes

• Commas: Spot the missing commas!
• Commas: Put the comma in the right place!