Are singular and plural versions of a word treated differently?
Some search engines distinguish between singular and plural versions of a word, while some don’t, so, particular care needs to be taken where both versions are likely to be used in search terms. If both singular and plural versions of words are to be targeted, then there are two options: either create two different pages that target the words separately; or, include both versions in the same page, which means including them both in the title and description of the page and using them both in your page copy.