Grammar Police People

[Jeremy]

Originally Posted by selena

One of the words on the list is class's.

Context is everything, apart from which particular Style Guide is in fashion.

Class as you've written it there is singular, no? As in, one class containing several people.

The Times publishes its, but it's a UK one which may not be in fashion in the US:

http://www.timesonline.co.uk/section/0,,2941,00.html

It recommends writing "as voiced".

EG:

The class's project. (One class, one project).
The class's projects. (One class, several projects).
The classes' project. (Several classes, one project).
The classes' projects. (Several classes, several projects).

[MorganGrayson]

From Strunk and White's The Elements of Style (regarded by many to be the "little Bible of writing," as it is clear, concise and based on what is coherent rather than what has been traditionally correct.)

"Form the possessive singular of nouns by adding 's"

They felt it enough of a pain in the ass to put it on page 1, too.

Put simply, points to Jeremy, he's right.