Just a query about punctuation.

[kate]

Could someone please confirm whether a comma is needed before or after a conjuction,I was always taught that no comma is required at either time but recently I have noticed newspapers and other texts doing just that. Is my understanding wrong?

[Flaminius]

I don't think comma is necessary after a conjunction. But commas in that position can indicate a pause held between the conjunction and succeeding elements of the sentence.

[Stargzer]

Could someone please confirm whether a comma is needed before or after a conjuction,I was always taught that no comma is required at either time but recently I have noticed newspapers and other texts doing just that. Is my understanding wrong?

If you are talking about creating a series of three, four, or five or more items, you need a comma to separate them. However, there has long been a debate as to whether a comma was needed after the next-to-the-last item in the series (i. e., after the "four" above). This also applies to a series of six, seven, eight, and nine or more items. I think it's more a matter of style than grammar. In a newspaper or something like the US Congressional Record, where a lot of stuff is printed on a daily basis, not using the last comma saved not only ink but also the lead type for a comma and the time to find and set it back in the old days of moveable type, long before word processors and word processing software on personal computers. Now that computers have replaced human typesetters the time involved no longer matters.

In part, the current GPO (Government Printing Office) Style Manual in part has this to say:

8.42. After each member within a series of three or more
words, phrases, letters, or figures used with and, or, or nor.

red, white, and blue
horses, mules, and cattle; but horses and mules and
cattle
by the bolt, by the yard, or in remnants
a, b, and c
neither snow, rain, nor heat
2 days, 3 hours, and 4 minutes (series); but 70 years 11
months 6 days (age)

8.43. Before the conjunction in a compound sentence
containing two or more independent clauses, each of which could
have been written as a simple sentence.

Fish, mollusks, and crustaceans were plentiful in the
lakes, and turtles frequented the shores.
The boy went home alone, and his sister remained with the
crowd.

Obviously, things can vary on your side of The Pond.

[Davekent]

The comma after the penultimate item in a list: first, second, and third is called a "Harvard comma." Some call it the "Oxford comma" or "serial comma."

It's a stylistic issue. Either way is correct. Technical writers prefer it as it lowers the risk of ambiguity. Journalists and advertisers think it merely takes up valuable space.

[Perry]

If only the Microsoft Word programmers would read this thread (and a few grammer texbooks while they are at it)!

[David McWethy]

I remember a situation I encountered during the reconstruction and remodeling of an historic old building: The part of the plans and specifications dealing with insulating the HVAC ducts, as prepared by the mechanical engineer, read:

All supply ducts and return air ducts located in the attic shall be lined on the inside with 1"...insulation....

The intention was clear (to the owner and the architect): The ducts to be insulated were those which supplied heated or cooled air, wherever they were located; and those return air ducts located in the uninsulated attic.

During one of my inspections I noticed some uninsulated supply-air ductwork being installed; when I brought this to the attention of the contractor he referred me to the contract documents portion, which he was reading as if it were written: The ducts to be insulated were only those supply ducts and return air ducts that were located in the attic; it was obvious, then, that no insulation was required for the ducts located in the between-floors plenum.

One phrase; two widely disparate interpretations (both of which were valid), all because of a missing comma. Had the phrase been written

All supply ducts, and return air ducts located in the attic, shall be lined on the inside with 1"...insulation.

it's meaning would have been crystal-clear.