(1) Apostrophes and plurals
We start by mentioning the primary rule again: in 99,982 percent of cases we should not use apostrophes when writing plural nouns in English. So photo’s, Mazda’s, pizza’s and Ferrari’s are incorrect if they are intended as plurals and not to indicate possession; the correct forms are photos, Mazdas, pizzas and Ferraris respectively.
Is an apostrophe ever permitted when writing plurals in English? According to the website of the Oxford Dictionary, yes. Some instances are:
– When writing the plural of letters of the alphabet, e.g. in sentences like: There are four s’s and two p’s in Mississippi; You must watch your p’s and q’s.
– When writing the plural of some abbreviations, e.g. We have received four cheques and two IOU's. “But,” the Oxford continues, “IOUs is common and accepted, and the usual plural of CD is CDs.”
Also permitted are apostrophes when we write the plural of numerals (e.g. the 1930’s), but this is not encouraged and the preferred form is the 1930s.
(2) Apostrophes and possessive forms
In “More about the apostrophe” we saw that while the possessive forms of names ending in s require an apostrophe plus s, e.g. James’s book, tradition has allowed an apostrophe to be added without another s in the case of some names. The names mentioned in that article were Moses and Jesus (possessives Moses’ and Jesus’ respectively). Some other names need to be added to that list, including Euripides, Demosthenes and Xerxes. The rule regarding this category is that the s-less possessive is allowed where the names have (i) more than one syllable and (ii) an unaccented ending pronounced “eez”.
And lastly (at least for now!), a note about the possessive of closely-linked nouns: If the entity possessed is the same for both nouns, only the second element takes the apostrophe, e.g. Jenny and Tom’s cat (the same cat). If the entities are different, two apostrophes are used, e.g. Jenny’s and Tom’s jobs (different jobs). – ws –