Usage of Commas in Lists

[SunnyDay]

I've been taught that when making a list of three or more items, you use a comma before the "and" in the list.

"He had apples, oranges, and pears."

If you leave out the comma, it's supposed to mean that the last two items are a unit.

"He had a door, a doorknob, and a lock and key."

(Even though there, I guess you're still using the comma before the first "and.")

The other day, though, my English teacher told me that you're supposed to leave out that last comma.

"He had apples, oranges and pears."
"He had a door, a doorknob and a lock and key."

Those last two look wrong to me, but, which is it?

EDIT: And if there's a difference between American English and British English in this, I'd like the American English one, please.

Thanks!

[phillip_l]

comma before and..i dunno if it's different in england though.
apples, oranges, and pears

you're right about the compound thing too.

[rewboss]

This is known as the "Oxford comma", and its use is disputed. Some say it must be used, others say it is nearly always useless.

Where there is no chance of confusion, as in "apples, oranges(,) and pears", I think you are justified in leaving it out. That's what most writers I know do. The logic is that if there are only two items, you don't write "apples, and pears" except in certain situations (usually, if "and pears" is considered an afterthought), so why should you write "apples, oranges, and pears"?

However, if the last list item itself includes a comma, then you should separate that item with a comma, as you do: "a doorknob, and a lock and key". This is a matter of courtesy to the reader: omitting the comma will initially make it look as if the last item is "lock", and when the reader comes to the second "and", they will be forced to "backtrack" a little and reread the last few items of the list.

So, in most cases, the Oxford comma is superfluous, but not (I would say) incorrect. However, this is a lose-lose situation, because there are people who passionately take up one side of the argument or the other...

[MrPedantic]

Yes; it's also known as the "serial comma".

I believe there is a slight AmE/BrE difference. In most British books, newspapers, and magazines, the tendency now is to omit the comma before "and". However, some academic publishers (Oxford University Press, Cambridge University Press) generally retain the comma. Secretarial courses and style manuals tend to suppress it.

In the US, on the other hand, the comma is still widespread in books and in general usage; though newspapers and magazines are more likely to omit it.

The serial comma started to disappear at the beginning of the 20th century. At one time, the comma was generally used to denote a pause, or as a indicator of cadence. (If you say "apples, pears and oranges" aloud, there's a natural pause before the "and".) Now, however, the comma is much more likely to be taken as an indicator of sense. This may reflect a movement away from reading with the ear, towards reading only with the eye.

MrP

[SunnyDay]

Darn picky comma rules.

Thanks, guys. :)