While colloquial uses of apostrophes are rapidly changing (as my boyfriend recently pointed out, MMO’s is the accepted pluralisation of this acronym), it is worth knowing the rules for academic and professional writing, as you’re far more likely to encounter the pedantic types who really care about grammar and punctuation in these areas. So here are the uses of apostrophes:
Contracted words are words which are either words with bits missing, or words consisting of two words put together, with bits missed out. E.g:
don’t (do not)
it’s (it is)
or the incredible naval term fo’c’sle (forecastle, referring to the upper deck of the ship)
notice in all of these that the apostrophe replaces the missing letter, it is don’t, not do’nt.
Though please note, normally contractions should not be used in academic writing, wherever possible, use the full form.
Apostrophes can denote ownership, such as “Mary’s hat”. This is the most commonly incorrectly used form as the apostrophe is often placed wrongly, or, these can be confused with plurals, leading to mistakes such as “apple’s”.
The rule is: for singular ownership, the apostrophe goes before the ‘s’:
The cat’s milk (one cat owns some milk)
For plural owners, the apostrophe goes after the ‘s’:
The cats’ food (food belonging to multiple cats)
the mothers’ children (multiple children belonging to multiple mothers)
Freshers’ Fair (the fair for many freshers)
There are however, some exceptions, which only make things more confusing… e.g.:
- The pronoun ‘it’ does not take an apostrophe to denote ownership, “it’s” always means the contracted form of “it is” and never “the thing belonging to ‘it'”, the correct way of writing “the thing belonging to ‘it'” is “its” as in: The creature chased its tail.
- Irregular nouns which look different when plural (i.e. those where something other than just “adding an ‘s'” happens, such as ‘mice’ or ‘children’ not ‘mouses’ or ‘childs’) have the apostrophe before the ‘s’ when plural to denote ownership, so not “the childrens’ coats” but “the children’s coats”
- There is the option, though many people choose seemingly arbitrarily on this rule, of using just an apostrophe, rather than apostrophe plus ‘s’ to denote ownership on words which end in ‘s’: “James’ book”, though many place names, and even the name of my old secondary school, choose to ignore this rule “King James’s Square” “Lord Williams’s School”
Apostrophes are never used to denote plurals. Not even plurals of acronyms such as “CD” or “CEO”, these are always CDs, CEOs, apples etc. Apostrophes are also not used to denote decades such as “the 80s”, though this is a rule which seems to be in a state of flux and may not continue to be correct usage for much longer as uses such as ‘the 80’s’ and ‘CD’s’ are frequently seen.