What is the optional plural form of a word that ends in “‑y”?

I guess “optional plural” is the correct term. I’m referring to things like

• It can be found at the following location(s).
• Please pick up your ticket(s).

But how do I do that to a word that ends in ‑y? Take category for example: “category(s)” doesn’t seem correct, because categorys is a misspelling. But everything else I have tried looks ridiculous.

What’s the correct approach here?

Words that end in -Cy regularly go to -ies, while those that end in -Vy regularly go to -Vys (where C means a consonant and V means a vowel).

• bunny > bunnies, telly > tellies, category > categories
• Monday > Mondays, boy > boys, monkey > monkeys

But money > monies is irregular.

You could write

• Please select your preferred category or categories.
• Please select your preferred category(-ies).
• Please select one or more categories.

Stackoverflow Content

If you have a computer program that does the equivalent of:

printf("%d %s(s) selected.\n", count, thingie);

Then you are automatically doing it wrong. A computer should know how to count. And inflect. It is pure laziness — and not the good kind, either — on the part of programmer to write

1 file(s) deleted.

That sort of thing is extremely aggravating. Please do not do it. In the specific case of having a category for a thingie, you would use

printf("%d categor%s selected.\n", count, count == 1 ? "y" : "ies");

Accept no substitutes.

In the more general case, you need an English noun inflector.

When you write category(s), or category(ies), or whatever, you are not writing an “optional plural” form of the word category. You are writing an abbreviation of the noun phrase “category (or categories)”.

To see this is so, ask yourself how you would pronounce category(s) and convey the intended meaning? You couldn’t. You would have to say something like “category (or categories)”, and that, then, is also how you would write it out.

How you abbreviate that noun phrase is up to you (and your editor or style guide, if you have one).

And notice that this isn’t even a question about English. This question and its answer apply to any written language in which you want to abbreviate a noun phrase containing both the singular and the plural form.