The serial comma is the comma that is used in lists of words. In most cases, it comes just before the last “and”. For Example:
a) Italy, Germany, and England. (This is written with the serial comma.)
b) Italy, Germany and England. (This is written without the serial comma.)
In the previous example, the meaning of the two sentences is identical. However, in some cases, the use of the comma can change the meaning of the sentence. Look at the following sentence:
“I would like to dedicate this song to my parents, John and Jane.” In this sentence there is ambiguity. From the way it is written, it could have two distinct meanings:
a) The song is dedicated to the writer’s parents, who are John and Jane.
b) The song is dedicated to the writer’s parents (whose names we don’t know), plus two other people: John and Jane.
Here is another example:
“My favourite types of sandwiches are tuna, ham and cheese.”
Without the serial comma, it isn’t clear if the writer likes two or three types of sandwiches:
a) I like two types of sandwiches: tuna sandwiches; and ham and cheese sandwiches.
b) I like three types of sandwiches: tuna sandwiches; ham sandwiches; and cheese sandwiches.
However, if you add the comma, the meaning is less ambiguous if you want to say that you like three sandwiches:
“My favourite types of sandwiches are tuna, ham, and cheese.”
Here is another example:
“I spoke to Sally, a police officer and a cook.”
This sentence is also somewhat ambiguous. Here are the three possible meanings:
a) I spoke to two people: Sally, who is a police officer; and a cook.
b) I spoke to three people: Sally; a police officer; and a cook.
c) I spoke to one person: Sally, who is both a police officer and a cook.
If you add the serial comma, it becomes a bit less ambiguous, although even with the serial comma it’s still a bit confusing. So, in this case it would probably be better to re-write the sentence.
So, as you can see, the serial comma is quite good in some cases when you want to avoid ambiguity. However, despite this, there is no consensus among writers or editors on the use of the serial comma. Oxford is in favour of the comma (hence the name, the Oxford Comma). The Oxford Style Manual (2002) says, “The last comma serves also to resolve ambiguity, particularly when any of the items are compound terms joined by a conjunction [such as ‘and’].” However, other publishers and publications argue that the Oxford Comma is against conventional practice and that it is better to improve the wording of the sentence in order to avoid the ambiguity. We at Hot English believe in being practical, and our policy is: if the Oxford Comma makes the sentence easier to understand, use it. What do you think?