It's happened again, my friends. I've flipped out over something that any normal human would simply ignore. I know that I overreact, but why oh why do writers use apostrophes when forming a simple plural?
My morning had been reasonably calm, a cappuccino on the deck while writing down my goals for the week before sitting down to the computer. Clearly, my mistake was checking a popular social networking site. A post that was intended as cute brought my blood to the boiling point. It was about yarn, for crying out loud. Basically, it said that we should keep yarn away from "cat's and kid's." "Cat's and kid's WHAT?" I screamed at my screen.
I think my anger escalated because the quotation had been added to an illustration, and it flowed perfectly around a line drawing of a woman crafting a list. The writer of the post had taken care with presentation but not with grammar. It was as if she carefully iced a cake before baking it.
How do we know when we need an apostrophe? It's easier to figure out when we don't need one. If you are writing about more than one object, it's plural. Plural nouns do not take apostrophes. I repeat, they do NOT take apostrophes. One cat, many cats; one dog, many dogs; one kid, many kids. See the pattern?
So when DO you need an apostrophe? The primary use is to show ownership. If you are writing about the sound that belongs to a cat, it's "the cat's meow." If you are writing about the end that belongs to a dog, it's "a dog's tail."
The location of the apostrophe can be a little tricky. If the noun is singular, the apostrophe goes between the singular noun (cat) and the "s" that indicates possession, as in "cat's." If you are writing about more than one cat, the apostrophe follows the plural noun. We have two cats, and if I'm writing about playthings they share, it's "the cats' toys." Our cats happen to be very proprietary, so if I'm writing about the toys that belong to one cat or the other, it would be "the cat's toys." Can you see why the position of the apostrophe is important?
There are numerous other occasions where the apostrophe is used, and it can be difficult to keep track of them all. For less common uses of the apostrophe, you should bookmark a reliable on-line resource, such as Grammar Girl's http://grammar.quickanddirtytips.com. It's a searchable guide that is easy to understand. An online resource for more scholarly writing is hosted by Purdue University: http://owl.english.purdue.edu/owl/resource/747/01/.
If you consider yourself a serious writer, you should invest in the style guide related to your field. These include the MLA Manual, the Chicago Manual of Style, and Gregg's Reference Manual. While you might not spend your free minutes reading the style guide to find interesting anomalies of grammar, it is a comfort to have it at hand, knowing that you will always be able to check your writing before you hit "Post."
P.S. When I went back to look at the offending social networking site's post, I found that it was gone. Do you think it was my comment that made it disappear?