Possessives versus Adjectival Labels :
Don't confuse an adjectival label (sometimes called an
attributive noun) ending in s with the need for a possessive.
Sometimes it's not easy to tell which is which. Do you attend a
writers' conference or a
writers conference? If it's a group of writers attending a conference, you want the plural ending, writers.
If the conference actually belongs to the writers, then you'd want the possessive form, writers'. If you can insert another modifer between the
-s word and whatever it modifies, you're probably dealing with a possessive.
Additional modifiers will also help determine which form to use.
Patriots quarterback Drew Bledsoe threw three touchdown passes. (plural as modifier)
The Patriots' [new] quarterback, Drew Bledsoe, threw three touchdown passes. (possessive as modifier]
Related Links :
Possessives with Gerunds
Possessives versus Adjectival Labels
Possessives of Plurals
Irregular Plurals
Holidays Showing Possession
Compound Possessives
Possessives Constructions
Compound Constructions
Possessives with Appositive Forms
Double Possessives