The Exemplar Possessive

A reader wrote to me recently regarding the Writer's Block CD, a product from my sponsors and publishers, The WCCL Network.

"Why is the apostrophe placed in front of the 's'?" he asked me. "Surely more than one person in the history of the world has suffered from this condition?"

I understood what he meant. The normal rule with possessives is that the apostrophe comes after the relevant noun. So the boy's room refers to a room belonging to one boy, while the boys' room signifies a room occupied by two or more. I discussed this in more detail a while ago in this blog post.

Writer's block is not really an exception to this rule, more a special case. Where the question of ownership is much less important than the nature or provenance of the item, a single 'exemplar' noun is often used for the possessive. I call this the exemplar possessive - I'm not sure if it has a more 'official' name. Here are a few more examples:

• goat's cheese
• cow's milk
• greengrocer's apostrophe
• cat's eyes (reflective safety devices on roads)
• collector's item

In some circumstances you can make a case either way, or even three different ways. Father's Day, for example, can be written in any of three ways:

Fathers Day - 'Fathers' here is seen as an adjective, like 'sports' in sports hall.
Father's Day - The exemplar possessive here signifies a day devoted to fathers and fatherhood in general.
Fathers' Day - The plural possessive here signifies a day belonging to all fathers.

None of these options is 'wrong', though each has a slightly different emphasis. If you're a dad, see whether and where an apostrophe appears on your cards on the day in question. Fun for all the family...

In other cases, however, the exemplar possessive is clearly required to avoid ambiguity. Suppose, for example, you have a recipe that includes among the ingredients six lamb's kidneys. Most people would understand this to mean that six kidneys from lambs - obviously not all from a single lamb - are required.

If, however, you wrote instead six lambs' kidneys (the plural possessive), it would be hard to avoid the conclusion that the recipe required the kidneys of six lambs, i.e. twelve kidneys in all. So in this case, using the exemplar possessive avoids any risk of confusing the cook!