Commas in Lists (Grammar Lesson)
The Quick AnswerWhen there are two items in a list, don't use a comma to separate the list items (unless it helps your reader). If there are more than two list items, then those following US convention should use a comma before the conjunction (usually and or or).
- Bread, milk, and cheese ()
- Bread, milk and cheese ()
Using Commas in ListsWhen there are two items in a list, there is no need to separate the list items with a comma. For example:
- Bread and cheese
- London and New York
When there are more than two items, the situation gets more complicated. Generally speaking, in the UK, writers tend not put a comma before the conjunction. In the US, however, writers tend to use a comma.
This delineation between UK and US is very general — there are plenty of organizations in both countries that do not adhere to this.
The Oxford CommaWhen a comma is used before the conjunction in a list, it is known as an Oxford Comma. Some people (mostly, but not exclusively, Brits) consider the Oxford Comma to be a waste of ink, while others (mostly, but not exclusively, Americans) strongly campaign for its inclusion. There really is no rule. You should follow whatever convention your company follows. If you don't have a company convention, then copy the convention used in a decent national newspaper. If you're free to make your own mind up, then pick a convention and be consistent. (That is the golden rule.)
- Bread, milk and cheese ( or those who don't use the Oxford Comma)
- Bread, milk, and cheese ( or those who do use the Oxford Comma)
- London, Paris and New York ( or those who don't use the Oxford Comma)
- London, Paris and New York ( or those who do use the Oxford Comma)
|Followers of the Oxford Comma
|Avoiders of the Oxford Comma|
There is another consideration. Sometimes, it is appropriate to break whatever convention you're following for the sake of clarity — even in a list with just two list items. For example:
- The news will be shown after Dangermouse, and Rug Rats. (Without the comma, people could think that Dangermouse and Rug Rats is one programme.)
- The train will stop at Harrow, Pinner, Watford, and Bushey. (Watford and Bushey could be one place, like Bath and Wells.)
- The emblem is an amalgamation of the British and Irish flags, the Stars and Stripes, and the Hammer and Sickle. (The word and appears lots of times in this example. The comma before the and makes it easier for the reader to identify the last list item.)
Using Lots of Adjectives (Enumeration of Adjectives)Especially in creative writing, there is a need to use several adjectives. The rules about using commas in a list of adjectives are far more relaxed. For example:
For TWO adjectives:
- vast, inhospitable moor (with a comma)
- vast and inhospitable moor (with and)
- vast inhospitable moor (with nothing)
- vast, inhospitable, windy moor (commas between)
- vast, inhospitable and windy moor
(comma(s) between and then and )
(With this style, follow your convention; i.e., put a comma before and if you advocate the Oxford Comma.)
- vast inhospitable windy moor (nothing between)
- vast inhospitable and windy moor (nothing and then and)
Beware Confusion with an Oxford CommaCommas can be used to introduce additional information (called parenthesis). For example:
- My friend, Simon, lives near the concrete cows in Milton Keynes. (In this example, commas are being used to add information about My friend.)
- I left the pub with my friend, Simon, and Terry. (In this sentence, it is unclear whether I left the pub with two people (My friend Simon and Terry) or three people (my unnamed friend, Simon and Terry).
- I left the pub with my friend, Simon and Terry. (In this sentence (without the Oxford Comma), there is no ambiguity. It has to be three people.)
- On the London Underground, the Bakerloo Line goes through Harrow and Wealdston, Paddington, Oxford Circus, and Elephant and Castle.
- On the London Underground, the Bakerloo Line goes through Harrow and Wealdston, Paddington, Oxford Circus and Elephant and Castle.
- The Bakerloo Line runs between Harrow and Wealdstone, and Elephant and Castle.
- The Bakerloo Line runs between Harrow and Wealdstone and Elephant and Castle.
Be Consistent – but Break Convention for ClarityFollow one of the conventions, and stick to it throughout your document. However, if you write something ambiguous, try to reword your sentence. If that proves too cumbersome, have the confidence to switch conventions in the same document. Above all, remember this:
Clarity trumps both conventions.
Read more about the Oxford Comma.